U.S. patent application number 09/195692 was filed with the patent office on 2001-10-11 for substrate-type non-reciprocal circuit element and integrated circuit having multiple ground surface electrodes and co-planar electrical interface.
Invention is credited to MARUHASHI, KENICHI, OHATA, KEIICHI.
Application Number | 20010028280 09/195692 |
Document ID | / |
Family ID | 18101189 |
Filed Date | 2001-10-11 |
United States Patent
Application |
20010028280 |
Kind Code |
A1 |
MARUHASHI, KENICHI ; et
al. |
October 11, 2001 |
SUBSTRATE-TYPE NON-RECIPROCAL CIRCUIT ELEMENT AND INTEGRATED
CIRCUIT HAVING MULTIPLE GROUND SURFACE ELECTRODES AND CO-PLANAR
ELECTRICAL INTERFACE
Abstract
A substrate-type non-reciprocal circuit element comprises a
substrate, a ferrite embedded in the substrate, a central electrode
formed on the ferrite at one principal surface of the substrate, a
plurality of signal conductors formed on the one principal surface
of the substrate to extend from the central electrode into a
plurality of different outward directions, a first ground electrode
formed on the one principal surface of the substrate, separately
from the central electrode and the plurality of signal conductors,
and a second ground electrode formed on the other principal surface
of the substrate and electrically connected to the first ground
electrode. Thus, the substrate-type non-reciprocal circuit element
can be easily electrically connected to a measurement machine, to
enable to precisely and easily measure an electrical
characteristics with a good repeatability. In addition, the
substrate-type non-reciprocal circuit element can be connected to
an electric circuit such as a receiver circuit and a transmitter
circuit with a low transmission loss and a low variation in the
transmission loss.
Inventors: |
MARUHASHI, KENICHI; (TOKYO,
JP) ; OHATA, KEIICHI; (TOKYO, JP) |
Correspondence
Address: |
MCGINN & GIBB, PLLC
INTELLECTUAL PROPERTY LAW
8321 OLD COURTHOUSE RD.
SUITE 200
VIENNA
VA
22182
US
|
Family ID: |
18101189 |
Appl. No.: |
09/195692 |
Filed: |
November 19, 1998 |
Current U.S.
Class: |
333/1.1 ;
333/24.2 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 2924/0002 20130101; H01P 1/387 20130101; H01L 2924/00
20130101 |
Class at
Publication: |
333/1.1 ;
333/24.2 |
International
Class: |
H01P 001/387 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 19, 1997 |
JP |
9-318621 |
Claims
1. A substrate-type non-reciprocal circuit element having a
plurality of signal conductors and so configured that a signal
inputted through one signal conductor is outputted from another
signal conductor, the substrate-type non-reciprocal circuit element
comprising a substrate, a ferrite embedded in said substrate, a
central electrode formed on said ferrite at one principal surface
of said substrate, a plurality of signal conductors formed on said
one principal surface of said substrate to extend from said central
electrode into a plurality of different outward directions, and a
first ground electrode formed on said one principal surface of said
substrate, separately from said central electrode and said
plurality of signal conductors.
2. A substrate-type non-reciprocal circuit element claimed in claim
1 wherein said first ground electrode is formed at opposite sides
of each of said signal conductors, separately from each of said
signal conductors so as to form a coplanar waveguide between each
of said signal conductors and said first ground electrode.
3. A substrate-type non-reciprocal circuit element claimed in claim
2 further including a reflectionless resistor located at the side
of said one principal surface of said substrate and connected
between one of said signal conductors and said first ground
electrode.
4. A substrate-type non-reciprocal circuit element claimed in claim
3 further including a second ground electrode formed on the other
principal surface of said substrate and electrically connected to
said first ground electrode.
5. A substrate-type non-reciprocal circuit element claimed in claim
4 wherein said second ground electrode is electrically connected to
said first ground electrode by a side surface electrode formed on a
side surface of said substrate.
6. A substrate-type non-reciprocal circuit element claimed in claim
4 wherein said second ground electrode is electrically connected to
said first ground electrode by through-holes formed to penetrate
through said substrate from said first ground electrode to said
second ground electrode.
7. A substrate-type non-reciprocal circuit element claimed in claim
1 further including a reflectionless resistor located at the side
of said one principal surface of said substrate and connected
between one of said signal conductors and said first ground
electrode.
8. A substrate-type non-reciprocal circuit element claimed in claim
7 further including a second ground electrode formed on the other
principal surface of said substrate and electrically connected to
said first ground electrode.
9. A substrate-type non-reciprocal circuit element claimed in claim
8 wherein said second ground electrode is electrically connected to
said first ground electrode by a side surface electrode formed on a
side surface of said substrate.
10. A substrate-type non-reciprocal circuit element claimed in
claim 8 wherein said second ground electrode is electrically
connected to said first ground electrode by through-holes formed to
penetrate through said substrate from said first ground electrode
to said second ground electrode.
11. A substrate-type non-reciprocal circuit element claimed in
claim 1 further including a second ground electrode formed on the
other principal surface of said substrate and electrically
connected to said first ground electrode.
12. A substrate-type non-reciprocal circuit element claimed in
claim 11 wherein said second ground electrode is electrically
connected to said first ground electrode by a side surface
electrode formed on a side surface of said substrate.
13. A substrate-type non-reciprocal circuit element claimed in
claim 11 wherein said second ground electrode is electrically
connected to said first ground electrode by through-holes formed to
penetrate through said substrate from said first ground electrode
to said second ground electrode.
14. An integrated circuit comprising an integrated circuit board
and a substrate-type non-reciprocal circuit element having a
plurality of signal conductors and so configured that a signal
inputted through one signal conductor is outputted from another
signal conductor, said substrate-type non-reciprocal circuit
element comprising a substrate, a ferrite embedded in said
substrate, a central electrode formed on said ferrite at one
principal surface of said substrate, a plurality of signal
conductors formed on said one principal surface of said substrate
to extend from said central electrode into a plurality of different
outward directions, and a first ground electrode formed on said one
principal surface of said substrate, separately from said central
electrode and said plurality of signal conductors, said
substrate-type non-reciprocal circuit element being electrically
connected to said integrated circuit board in a flip chip
method.
15. An integrated circuit claimed in claim 14 wherein said first
ground electrode is formed at opposite sides of each of said signal
conductors, separately from each of said signal conductors so as to
form a coplanar waveguide between each of said signal conductors
and said first ground electrode.
16. An integrated circuit claimed in claim 15 wherein said
substrate-type non-reciprocal circuit element further includes a
reflectionless resistor located at the side of said one principal
surface of said substrate and connected between one of said signal
conductors and said first ground electrode.
17. An integrated circuit claimed in claim 16 wherein said
substrate-type non-reciprocal circuit element further includes a
second ground electrode formed on the other principal surface of
said substrate and electrically connected to said first ground
electrode.
18. An integrated circuit claimed in claim 17 wherein said second
ground electrode is electrically connected to said first ground
electrode by a side surface electrode formed on a side surface of
said substrate.
19. An integrated circuit claimed in claim 17 wherein said second
ground electrode is electrically connected to said first ground
electrode by through-holes formed to penetrate through said
substrate from said first ground electrode to said second ground
electrode.
20. An integrated circuit claimed in claim 17 wherein said
substrate-type non-reciprocal circuit element is accommodated in a
recess formed in said integrated circuit board.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a substrate-type
non-reciprocal circuit element and an integrated circuit using the
same, and more specifically to a substrate-type non-reciprocal
circuit element, such as a circulator and an isolator, suitably
used in a high frequency circuit, and an integrated circuit using
the same.
[0003] 2. Description of Related Art
[0004] One example of a prior art non-reciprocal circuit element is
disclosed in U.S. Pat. No. 5,419,947, the content of which is
incorporated by reference in its entirety into this application. Of
the non-reciprocal circuit element, one example of the
substrate-type non-reciprocal circuit element is shown in FIG. 7
which is a diagrammatic perspective view illustrating a
substrate-type circulator, which is one example of a three-terminal
circulator.
[0005] This substrate-type circulator includes a substrate 1 and a
ferrite 2 embedded in the substrate 1. A central electrode pattern
3 is formed on an upper surface of the ferrite 2, and lead-out
conductors (signal conductors) 4 are formed on an upper surface (or
one principal surface) 1a of the substrate 1 to extend from the
central electrode pattern 3 in three different radially-outward
directions A ground electrode 5 is formed on a lower surface (or
the other principal surface) of the substrate 1.
[0006] This substrate-type circulator is put on a carrier member
and is conveyed in that condition, and thereafter mounted on a
circuit board. For example, when the substrate-type circulator is
connected to a transceiver circuit board (device), the respective
lead-out conductors 4, which constitute connection terminals, are
connected to corresponding electrodes on the circuit board by means
of a wire bonding or another.
[0007] In an actual operation, it is an ordinary practice to
position a magnet (not shown) above the ferrite 2. Thus, this
substrate-type circulator has such a non-reciprocal feature that a
signal applied to one lead-out conductor 4 is never returned to the
same lead-out conductor 4 but is outputted from another lead-out
conductor 4.
[0008] Here, if one terminal of the substrate-type circulator is
terminated with a matching load, the substrate-type circulator can
be converted into a substrate-type non-reciprocal circuit element
having a function as an isolator.
[0009] For example, the above mentioned substrate-type circulator
can be operated as an isolator, if one lead-out conductor 4 is
grounded through a reflectionless resistor. In this case, the
reflectionless resistor can be obtained by forming a thin film
resistor on the substrate 1. In the thin film resistor, however, it
is generally difficult to precisely control the resistance, and
therefore, the resistance of the thin film resistor is adjusted by
a trimming such as a laser trimming.
[0010] In the prior art substrate-type circulator, variation of the
size inevitably occurs in a manufacturing process, for example, in
a process for embedding the ferrite 2 into the substrate 1, and in
a process for forming the central electrode pattern 3. As a result,
the high frequency characteristics of the circulator varies, and
therefore, it was necessary to conduct a sorting with reference to
an appearance and an electric characteristics.
[0011] In the case of this substrate-type circulator, since the
variation of the size gives a large influence to a high frequency
characteristics in a very high frequency region such as a
millimeter wave band, it is necessary to adopt a reliable
characteristic evaluation method for the sorting.
[0012] In this very high frequency region, on the other hand, it is
not so easy to realize a good electrical connection between the
substrate-type circulator before the mounting and a characteristic
evaluation machine, and therefore, it is difficult to precisely
conduct a large amount of sorting. Even if there is used a test
fixture so configured to catch the substrate 1 between a pair of
members so as to cause the terminals of the circulator, namely, the
lead-out conductors 4 to be pressure-connected to connector
terminals, it is difficult to measure a large number of
substrate-type circulators in the millimeter wave band with a good
repeatability.
[0013] In addition, when the lead-out conductors 4 are connected to
electrodes of the circuit board by means of the wire bonding, the
wiring length becomes as long as about 100 .mu.m to 500 .mu.m
because of a mounting margin of the circuit board. Furthermore,
because of a restriction in the mounting precision, it is difficult
to maintain the length of the wire at a constant value. In the very
high frequency region such as the millimeter wave band, therefore,
a reflection loss attributable to an inductance of the wire and
variation in the inductance of the wire give a large influence to a
transmission characteristics, with the result that it was difficult
to connect between the transceiver circuit and the substrate-type
circulator with a low loss and with a small variation in the
loss.
[0014] This problem is also true in the case that the
substrate-type circulator is used as the isolator.
[0015] Furthermore, when the substrate-type circulator is used as
the isolator, it is also difficult to surely evaluate the electric
characteristics of the isolator in the very high frequency region
such as the millimeter wave band, similarly to the circulator. In
addition, it was difficult to evaluate and to adjust the thin film
resistor.
[0016] Therefore, there is a strong demand to perform the
evaluation of the electric characteristics and the evaluation and
the adjustment of the thin film resistor, before the mounting, by a
means having a very simple construction.
SUMMARY OF THE INVENTION
[0017] Accordingly, it is an object of the present invention to
provide a substrate-type non-reciprocal circuit element which has
overcome the above mentioned problems of the prior art.
[0018] Another object of the present invention is to provide a
substrate-type non-reciprocal circuit element, enabling to easily
measure the electric characteristics of the substrate-type
non-reciprocal circuit element with a high precision and a high
repeatability, thereby to easily and precisely perform the sorting
before the mounting.
[0019] Still another object of the present invention is to provide
a substrate-type non-reciprocal circuit element, enabling to
electrically connect the substrate-type non-reciprocal circuit
element on a circuit board such as a transceiver circuit board,
with a small loss and with a small variation in the loss.
[0020] A further object of the present invention is to provide an
integrated circuit incorporating therein a substrate-type
non-reciprocal circuit element.
[0021] The above and other objects of the present invention are
achieved in accordance with the present invention by a
substrate-type non-reciprocal circuit element having a plurality of
signal conductors and so configured that a signal inputted through
one signal conductor is outputted from another signal conductor,
the substrate-type non-reciprocal circuit element comprising a
substrate, a ferrite embedded in the substrate, a central electrode
formed on the ferrite at one principal surface of the substrate, a
plurality of signal conductors formed on the one principal surface
of the substrate to extend from the central electrode into a
plurality of different outward directions, and a first ground
electrode formed on the one principal surface of the substrate,
separately from the central electrode and the plurality of signal
conductors.
[0022] Specifically, the first ground electrode is formed at
opposite sides of each of the signal conductors, separately from
each of the signal conductors, so as to form a coplanar waveguide
between each of the signal conductors and the first ground
electrode.
[0023] In one embodiment, a reflectionless resistor is located at
the side of the one principal surface of the substrate and is
connected between one of the signal conductors and the first ground
electrode.
[0024] Preferably, a second ground electrode is formed on the other
principal surface of the substrate and is electrically connected to
the first ground electrode. This second ground electrode can be
electrically connected to the first ground electrode by a side
surface electrode formed on a side surface of the substrate or by
through-holes formed to penetrate through the substrate from the
first ground electrode to the second ground electrode.
[0025] According to another aspect of the present invention, there
is provided an integrated circuit comprising an integrated circuit
board and the substrate-type non-reciprocal circuit element as
mentioned above, the substrate-type non-reciprocal circuit element
being electrically connected to the integrated circuit board in a
flip chip method.
[0026] In one embodiment, the substrate-type non-reciprocal circuit
element is accommodated in a recess formed in the integrated
circuit board.
[0027] In the above mentioned substrate-type non-reciprocal circuit
element in accordance with the present invention, since the
plurality of signal conductors extending from the central electrode
in the plurality of different directions and the first ground
electrode are formed on the one principal surface of the substrate,
if a probe having a plurality of contacting terminals located in
the same plane is used, it is possible to realize a good electrical
contact between the probe and the substrate-type non-reciprocal
circuit element in a very high frequency region such as the
millimeter wave band.
[0028] Therefore, the substrate-type non-reciprocal circuit element
can be easily electrically connected to a measurement machine,
whereby an electrical characteristics can be precisely and easily
measured with a good repeatability.
[0029] In addition, since the plurality of signal conductors
extending from the central electrode in the plurality of different
directions and the first ground electrode are formed on one
principal surface of the substrate, the substrate-type
non-reciprocal circuit element is simple in construction.
[0030] Furthermore, in the integrated circuit mentioned above in
accordance with the present invention, since the signal conductors
and the ground electrode are formed on the same principal surface
of the substrate of the substrate-type non-reciprocal circuit
element, the signal conductors and the ground electrode of the
substrate-type non-reciprocal circuit element can be connected to
signal conductors and a ground electrode of a coplanar waveguide
formed on the integrated circuit board, respectively, by means of
the bumps with an extremely short connection distance. Therefore,
when the substrate-type non-reciprocal circuit element is connected
to an electric circuit such as the receiver circuit and the
transmitter circuit, the transmission loss itself and the variation
in the transmission loss can be minimized.
[0031] The above and other objects, features and advantages of the
present invention will be apparent from the following description
of preferred embodiments of the invention with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a diagrammatic perspective view of a
substrate-type circulator which is a first embodiment of the
substrate-type non-reciprocal circuit element in accordance with
the present invention;
[0033] FIG. 2 is a diagrammatic perspective view of a
substrate-type circulator which is a second embodiment of the
substrate-type non-reciprocal circuit element in accordance with
the present invention;
[0034] FIG. 3 is a diagrammatic perspective view of a
substrate-type isolator which is a third embodiment of the
substrate-type non-reciprocal circuit element in accordance with
the present invention;
[0035] FIG. 4 is a diagrammatic perspective view of one embodiment
of the integrated circuit in accordance with the present invention
using the substrate-type non-reciprocal circuit element in
accordance with the present invention:
[0036] FIG. 5 is an enlarged diagrammatic perspective view for
illustrating the mounting region of the integrated circuit board
and the substrate-type circulator to be mounted on the mounting
region, in the integrated circuit shown in FIG. 4;
[0037] FIG. 6, there is shown a diagrammatic perspective view of
another embodiment of the integrated circuit in accordance with the
present invention using the substrate-type non-reciprocal circuit
element in accordance with the present invention; and
[0038] FIG. 7 is a diagrammatic perspective view illustrating the
prior art substrate-type circulator.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] Now, embodiments of the substrate-type non-reciprocal
circuit element in accordance with the present invention and the
integrated circuit in accordance with the present invention will be
described with reference to the drawings.
First Embodiment
[0040] Referring to FIG. 1, there is shown a diagrammatic
perspective view of a substrate-type circulator which is a first
embodiment of the substrate-type non-reciprocal circuit element in
accordance with the present invention. The shown substrate-type
circulator includes a substrate 1 formed of a dielectric material
and a ferrite 2 in the form of a circular cylinder embedded in the
substrate 1. An central electrode pattern 3 is formed on an upper
surface of the ferrite 2 which is coplanar with an upper surface
(namely, one principal surface) of the substrate 1. In addition, a
plurality of lead-out conductors (signal conductors) 4 are formed
on the upper surface 1a of the substrate 1 to extend from the
central electrode pattern 3 in a plurality of radially outward
directions. In the shown embodiment, the lead-out conductors 4 are
formed to extend in three different directions, so that a
three-terminal circulator is constituted.
[0041] Furthermore, first ground electrodes 11 are formed on the
upper surface 1a of the substrate 1 to surround the central
electrode pattern 3 and to be positioned at opposite sides of each
of the lead-out conductors 4, but separately from the central
electrode pattern 3 and the lead-out conductors 4, so that a
coplanar waveguide 12 (which is one kind of surface strip
transmission line) is constituted of the lead-out conductors 4 and
the first ground electrodes 11 at the opposite sides of each of the
lead-out conductors 4. The first ground electrodes 11 are
electrically connected to a second ground electrode 13 formed on a
lower surface (or the other principal surface) 1b of the substrate
1 through side surface electrodes 14 formed on a side surface of
the substrate 1.
[0042] In order to evaluate the electric characteristics of this
substrate-type circulator, for example, a coplanar type high
frequency probe can be used which includes a plurality of pins
located in the same plane in the order of a ground pin, a signal
pin and a ground pin. This coplanar type high frequency probe is
applied to the substrate-type circulator in such a manner that the
ground pin, the signal pin and the ground pin of the coplanar type
high frequency probe are brought into contact with the first ground
electrode 11, the lead-out conductor 4 and the first ground
electrode 11 of the coplanar waveguide 12, respectively. In this
condition, a good electrical connection can be realized between the
substrate-type circulator and a characteristics evaluation machine
connected to the high frequency probe, in a very high frequency
region such as a millimeter wave band. This becomes possible by
forming the lead-out conductors 4 and the ground plane (the first
ground electrodes 11 in this first embodiment) in the same plane so
that the coplanar type high frequency probe can be contacted to the
lead-out conductors 4 and the ground plane of the substrate-type
circulator simultaneously.
[0043] For example, if the substrate-type circulator of this
embodiment is fixed on a sample stage by action of suction and the
electric characteristics is measured and evaluated by contacting
the coplanar type high frequency probe to the coplanar waveguide 12
of the substrate-type circulator, it is possible to efficiently and
reliably sort a large number of substrate-type circulators before
the mounting, for a limited period of time. This simple measurement
and evaluation was impossible in the prior art substrate-type
circulator mentioned hereinbefore, since no ground electrode is
formed on the upper surface of the substrate.
[0044] In the substrate-type circulator of this embodiment, since
the coplanar waveguide 12 is constituted of the lead-out electrodes
4 and the first ground electrodes 11 by forming the first ground
electrodes 11 at the outside of the central electrode pattern 3 and
the lead-out electrodes 4 on the same upper surface of the
substrate 1 as the surface on which the central electrode pattern 3
and the lead-out electrodes 4 are formed, if a probe having a
plurality of contacting terminals or pins located in the same plane
is used, it is possible to realize a good electrical contact in the
very high frequency region such as the millimeter wave band.
Accordingly, since it is possible to easily electrically connect
between the substrate-type circulator and a measuring machine, it
is possible to precisely and easily measure the electric
characteristics with a good repeatability.
[0045] In addition, since a plurality of lead-out conductors 4
extending from the central electrode pattern 3 in a plurality of
radially outward directions and the first ground electrodes 11 are
formed on the upper surface 1a of the substrate 1, the
substrate-type circulator is simple in construction, and the
electric characteristics can be easily measured.
Second Embodiment
[0046] Referring to FIG. 2, there is shown a diagrammatic
perspective view of a substrate-type circulator which is a second
embodiment of the substrate-type non-reciprocal circuit element in
accordance with the present invention. In FIG. 2, elements
corresponding to those shown in FIG. 1 are given the same Reference
Numerals.
[0047] This shown substrate-type circulator includes a substrate 1
formed of a dielectric material and a ferrite 2 in the form of a
circular cylinder embedded in the substrate 1. A central electrode
pattern 3 is formed on an upper surface of the ferrite 2 which is
coplanar with an upper surface of the substrate 1. In addition, a
plurality of lead-out conductors (signal conductors) 4 are formed
on the upper surface 1a of the substrate 1 to extend from the
central electrode pattern 3 in a plurality of radially outward
directions. Furthermore, first ground electrodes 11 are formed on
the upper surface 1a of the substrate 1 to surround the central
electrode pattern 3 and the lead-out conductors 4, separately from
the central electrode pattern 3 and the lead-out conductors 4, so
that a coplanar waveguide 12 is constituted of the lead-out
conductors 4 and the first ground electrodes 11.
[0048] In this second embodiment, the first ground electrodes 11
are electrically connected to a second ground electrode 13 formed
on a lower surface 1b of the substrate 1 by through-holes 21 formed
to penetrate through the substrate 1 from the first ground
electrodes 11 to the second ground electrode 13.
[0049] As seen from the above, the substrate-type circulator of the
second embodiment is the same as the substrate-type circulator of
the first embodiment, excepting that the through-holes 21 are used
in place of the side surface electrodes 14. Therefore, in the
substrate-type circulator of the second embodiment, an advantage
similar to that obtained in the substrate-type circulator of the
first embodiment can be obtained.
Third Embodiment
[0050] Referring to FIG. 3, there is shown a diagrammatic
perspective view of a substrate-type isolator which is a third
embodiment of the substrate-type non-reciprocal circuit element in
accordance with the present invention. In FIG. 3, elements
corresponding to those shown in FIG. 1 are given the same Reference
Numerals, and explanation will be omitted.
[0051] This shown substrate-type isolator is so constructed that,
in the substrate-type circulator of the first embodiment, one of
the three lead-out conductors 4, which are three terminals of the
substrate-type circulator, is connected to the first ground
electrode 11 through a reflectionless resistor 31 formed of for
example a thin film on the principal surface of the substrate
1.
[0052] In this substrate-type isolator, since the reflectionless
resistor 31 is connected to the first ground electrode 11
positioned near to the lead-out conductor 4, a parasite component
(inductance and capacitance) can be reduced in comparison with the
case that the reflectionless resistor is grounded at the exterior
of the substrate 1. Accordingly, this is advantageous to elevate
the high frequency characteristics of the isolator. In addition,
this substrate-type isolator can realize a good electrical
connection between the substrate-type isolator and the evaluation
machine in the very high frequency region such as the millimeter
wave band, similarly to the substrate-type circulator of the first
embodiment. Accordingly, it is possible to precisely and certainly
sort a large number of substrate-type isolators for a limited
period of time.
[0053] Furthermore, since it is possible to evaluate the
substrate-type isolator before the mounting, by a simple
construction, similarly to the substrate-type circulator of the
first embodiment, it is possible to relatively easily obtain a
desired high frequency characteristics by repeating the adjustment
of the resistance of the reflectionless resistor 31 formed of the
thin film, by means of the trimming typified by the laser trimming,
and the evaluation of the electric characteristics of the isolator.
If necessary, it is also possible to adjust the resistance while
conducting the measurement for the characteristics evaluation.
[0054] In this embodiment, the first ground electrode 11 and the
second ground electrode 13 are interconnected by the side surface
electrodes 14, similarly to the substrate-type circulator of the
first embodiment. However, it would be a matter of course that the
first ground electrode 11 and the second ground electrode 13 are
interconnected by through-holes, similarly to the substrate-type
circulator of the second embodiment.
[0055] In the substrate-type isolator of this embodiment, since the
coplanar waveguide 12 is formed of the lead-out conductor 4 and the
first ground electrodes 11 on the same plane, a large number of
substrate-type isolators before the mounting, operating in a very
high frequency region, can be precisely sorted for a limited period
of time, and in addition, the reflectionless resistor 31 formed of
the thin film for the isolator can be easily evaluated and adjusted
by means of a simple construction.
[0056] In connection with the first to third embodiments mentioned
above, the shape of the central electrode pattern 3 is not
specified, however, any shape can be applied if it is a
conventional shape used in the prior art. Furthermore, an external
magnet is not shown in the drawings and is not described in the
above explanation, however, it is a matter of course to persons
skilled in the art that the external magnet can be located above or
under the substrate-type circulator or isolator, or can be embedded
in the substrate 1. In addition, if the ferrite 2 is formed of a
hard ferrite material, since the external magnet becomes
unnecessary, the circulator and the isolator can be further
miniaturized.
Fourth Embodiment
[0057] Referring to FIG. 4, there is shown a diagrammatic
perspective view of one embodiment of the integrated circuit in
accordance with the present invention using the substrate-type
non-reciprocal circuit element in accordance with the present
invention.
[0058] The shown integrated circuit includes an integrated circuit
board 43 on which a transmitter circuit 41 and a receiver circuit
42 are formed. A mounting region 48, on which a substrate-type
circulator 47 is to be mounted is confined on an upper surface of
the integrated circuit board 43 between the transmitter circuit 41
and the receiver circuit 42 and separately from each of the
transmitter circuit 41 and the receiver circuit 42. In addition,
three signal conductors 49 are formed on the upper surface of the
integrated circuit board 43 in such a manner that, a first one of
the three signal conductors 49 extends straight from the
transmitter circuit 41 to the mounting region 48, a second one of
the three signal conductors 49 extends straight from the receiver
circuit 42, to the mounting region 48, and a third one of the three
signal conductors 49 extends straight from the mounting region 48
to an edge of the substrate 43 to be connected to an antenna 46. A
ground electrode 44 is formed on the upper surface of the
integrated circuit board 43 other than the transmitter circuit 41,
the receiver circuit 42 and the signal conductors 49, separately
from the three signal conductors 49 but to partially overlap with a
periphery of the mounting region 48, so that three coplanar
waveguides 45 are formed by the three signal conductors 49 and the
ground electrode 44 surrounding each of the three signal conductors
49, separately from the three signal conductors 49. In this
embodiment, the substrate-type circulator 47 is either the
substrate-type circulator of the first embodiment or the
substrate-type circulator of the second embodiment.
[0059] FIG. 5 is an enlarged diagrammatic perspective view for
illustrating the mounting region 48 of the integrated circuit board
43 and the substrate-type circulator 47 to be mounted on the
mounting region 48. As shown in FIG. 5, bumps 50 formed of for
example Au are formed on the signal conductors 49 and the ground
electrode 44 within the mounting region 48. On the other hand, the
substrate-type circulator 47 is positioned to have the surface of
the coplanar waveguide 12 faced to the mounting region 48 (namely,
the upper surface of the substrate 43), and then, is mounted on the
mounting region 48. This mounting can be realized by a method used
in a flip chip mounting method, for example, a thermocompression
bonding, a heat-fusion bonding, or a method utilizing a shrinkage
of an organic material.
[0060] In the substrate-type circulator 47 of this embodiment,
since the coplanar waveguide 12 is formed on the surface of the
substrate 1, the signal conductors and the ground electrode of the
coplanar waveguide 12 can be connected to the signal conductors 49
and the ground electrode 44 of the coplanar waveguide 45 formed on
the integrated circuit board 43, respectively, by means of the
bumps 50 with an extremely short connection distance which is
sufficiently smaller than 100 .mu.m. Therefore, the transmission
loss itself and the variation in the transmission loss can be
minimized, so that the substrate-type circulator can be connected
to the transmitter circuit and the receiver circuit with a
minimized loss.
[0061] Incidentally, the integrated circuit board 43 can be formed
of a dielectric material substrate which is conventionally used in
the prior art, but may be formed of a semiconductor substrate.
Fifth Embodiment
[0062] Referring to FIG. 6, there is shown a diagrammatic
perspective view of another embodiment of the integrated circuit in
accordance with the present invention using the substrate-type
non-reciprocal circuit element in accordance with the present
invention.
[0063] The shown integrated circuit includes an integrated circuit
board 61 having a recess 62 in which a substrate-type circulator 47
is to be accommodated. The integrated circuit board 61 also has a
recess 63 in which a transmitter circuit chip or substrate is to be
accommodated, and a recess 64 in which a receiver circuit chip or
substrate is to be accommodated. On the bottom of the recess 62, a
mounting region 48 similar to the mounting region 48 of the fourth
embodiment is formed. Thus, the substrate-type circulator 47 is
mounted on the mounting region 48 in such a condition that the
surface of the coplanar waveguide 12 is faced to the mounting
region 48 in the bottom of the recess 62. Interconnection between
the recesses 62, 63 and 64 and interconnection to an external are
realized by a coplanar waveguide 65 formed in the inside of the
integrated circuit board 61.
[0064] In the integrated circuit of this embodiment, the
transmission loss in the interconnections between the circuit chips
or substrates and between the circuit element and the circuit chips
or substrates can be minimized, and also, the variation in the
transmission loss can be minimized. In addition, if the recesses
62, 63 and 64 accommodating the circuit element and the circuit
chips or substrates, respectively, are covered with a lid, an
air-tight structure can be easily obtained. If the lid is formed of
an electrically conductive material, each of the recesses 62, 63
and 64 can be electromagnetically shielded.
[0065] The number of the recesses 62 to 64 is not limited to the
number in the shown embodiment, but any number of recesses can be
formed. In any case, it is possible to cause the recesses to
accommodate the transmitter circuit chip, the receiver circuit
chip, and a chip or substrate on which there is formed a portion or
all of a circuit required to operate the transmitter circuit and
the receiver circuit.
[0066] In the fourth and fifth embodiments, the substrate-type
circulator 47 is used as the substrate-type non-reciprocal circuit
element. However, it would be a matter of course to persons skilled
in the art that the substrate-type isolator of the third embodiment
can be used in place of the substrate-type circulator 47.
[0067] In addition, in the fourth and fifth embodiments, an
external magnet has not been explained. However, it would also be a
matter of course to persons skilled in the art that the external
magnet can be located under a rear surface of the integrated
circuit board 43 or 61, or above the substrate-type circulator 47
or the substrate-type isolator, or can be embedded in the substrate
of the substrate-type circulator or isolator. In addition, if the
ferrite is formed of a hard ferrite material, since the external
magnet becomes unnecessary. Furthermore, if the substrate-type
circulator or isolator including the ferrite formed of a hard
ferrite material is used in the integrated circuit of the fifth
embodiment, it is possible to easily realize a small-sized
integrated circuit having the integrated circuit board 61 of an
air-tight internal structure.
[0068] As mentioned above, in the substrate-type non-reciprocal
circuit element in accordance with the present invention, since the
plurality of conductors extending from the central electrode in the
plurality of different directions and the first ground electrode
are formed on one principal surface of the substrate, if the probe
having a plurality of contacting terminals located in the same
plane is used, it is possible to realize a good electrical contact
between the probe and the substrate-type non-reciprocal circuit
element in a very high frequency region such as the millimeter wave
band.
[0069] Therefore, since the substrate-type non-reciprocal circuit
element can be easily electrically connected to a measurement
machine, an electrical characteristics can be precisely and easily
measured with a good repeatability.
[0070] In addition, since the plurality of conductors extending
from the central electrode in the plurality of different directions
and the first ground electrode are formed on one principal surface
of the substrate, the substrate-type non-reciprocal circuit element
is simple in construction.
[0071] Furthermore, in the integrated circuit in accordance with
the present invention, since the signal conductors and the ground
electrode are formed on the one principal surface of the substrate
of the substrate-type non-reciprocal circuit element, the signal
conductors and the ground electrode of the substrate-type
non-reciprocal circuit element can be connected to the signal
conductors and the ground electrode of the coplanar waveguide
formed on the integrated circuit board, respectively, by means of
the bumps with an extremely short connection distance. Therefore,
when the substrate-type non-reciprocal circuit element is connected
to an electric circuit such as the receiver circuit and the
transmitter circuit, the transmission loss itself and the variation
in the transmission loss can be minimized.
[0072] The invention has thus been shown and described with
reference to the specific embodiments. However, it should be noted
that the present invention is in no way limited to the details of
the illustrated structures but changes and modifications may be
made within the scope of the appended claims.
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