U.S. patent application number 12/536931 was filed with the patent office on 2010-02-11 for techniques for mounting a millimeter wave antenna and a radio frequency integrated circuit onto a pcb.
This patent application is currently assigned to WILOCITY, LTD.. Invention is credited to Jorge MYSZNE, Yair SHEMESH.
Application Number | 20100033393 12/536931 |
Document ID | / |
Family ID | 41652430 |
Filed Date | 2010-02-11 |
United States Patent
Application |
20100033393 |
Kind Code |
A1 |
MYSZNE; Jorge ; et
al. |
February 11, 2010 |
Techniques for Mounting a Millimeter Wave Antenna and a Radio
Frequency Integrated Circuit Onto a PCB
Abstract
A printed circuit board (PCB) assembled to include at least one
millimeter wave antenna and a radio frequency integrated circuit
(RF IC). The PCB comprises a square-shaped cavity in the PCB,
wherein one of the edges of the cavity is substantially parallel to
connecting pins of the at least one millimeter wave antenna; a RF
IC placed in the cavity, wherein one side of the RF IC including RF
pads is substantially at the edge of the cavity that is
substantially parallel to the connecting pins; and traces
connecting the RF pads and the connecting pins, wherein the
connection between the at least one millimeter wave antenna and the
RF IC shortens the length of the traces.
Inventors: |
MYSZNE; Jorge; (Zikhron
Ya'akov, IL) ; SHEMESH; Yair; (Haifa, IL) |
Correspondence
Address: |
MYERS WOLIN, LLC
100 HEADQUARTERS PLAZA, North Tower, 6th Floor
MORRISTOWN
NJ
07960-6834
US
|
Assignee: |
WILOCITY, LTD.
Caesarea
IL
|
Family ID: |
41652430 |
Appl. No.: |
12/536931 |
Filed: |
August 6, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61086924 |
Aug 7, 2008 |
|
|
|
Current U.S.
Class: |
343/793 ; 29/428;
343/904 |
Current CPC
Class: |
H01Q 9/285 20130101;
H04B 7/26 20130101; H01Q 1/22 20130101; H01Q 3/24 20130101; Y10T
29/49826 20150115 |
Class at
Publication: |
343/793 ;
343/904; 29/428 |
International
Class: |
H01Q 1/00 20060101
H01Q001/00; H01Q 9/16 20060101 H01Q009/16 |
Claims
1. A method for mounting a millimeter wave antenna and a radio
frequency integrated circuit (RF IC) onto a printed circuit board
(PCB), comprising: forming a square-shaped cavity in the PCB
wherein one of edges of the cavity is substantially parallel to
connecting pins of the millimeter wave antenna, wherein the
millimeter wave antenna is printed on a first substrate layer of
the PCB; placing the RF IC in the cavity by positioning one side of
the RF IC including RF pads substantially at the edge of the cavity
that is substantially parallel to the connecting pins; and bonding
the RF pads and the connecting pins.
2. The method of claim 1, wherein a depth of the cavity is
substantially the same as a height of the RF IC.
3. The method of claim 1, wherein the RF pads include inputs and
outputs of RF signals to the RF IC.
4. The method of claim 1, wherein the RF IC is in a form of a
silicon die.
5. The method of claim 1, wherein the millimeter wave antenna
operates in millimeter wave bands including at least one of: 60 GHz
and 77 GHz.
6. The method of claim 1, wherein the millimeter wave antenna is at
least a quasi-omni printed dipole antenna.
7. A printed circuit board (PCB) assembled to include at least one
millimeter wave antenna and a radio frequency integrated circuit
(RF IC), comprising: a square-shaped cavity in the PCB, wherein one
edge of the cavity is substantially parallel to connecting pins of
the at least one millimeter wave antenna; a RF IC placed in the
cavity, wherein one side of the RF IC including RF pads is
substantially at the edge of the cavity that is substantially
parallel to the connecting pins, wherein the millimeter wave
antenna is printed on a first substrate layer of the PCB; and
traces connecting the RF pads and the connecting pins, wherein the
connection between the at least one millimeter wave antenna and the
RF IC shortens the length of the traces.
8. The PCB of claim 7, wherein a depth of the cavity is
substantially the same as a height of the RF IC.
9. The PCB of claim 7, wherein the RF pads include inputs and
outputs of RF signals to the RF IC.
10. The PCB of claim 7, wherein the RF IC is in a form of a silicon
die.
11. The PCB of claim 7, wherein the millimeter wave antenna
operates in millimeter wave bands including at least one of: 60 GHz
and 77 GHz.
12. The PCB of claim 7, wherein the millimeter wave antenna is at
least a qusi-omni printed dipole antenna.
13. The PCB of claim 12, wherein the millimeter wave antenna
comprises a pair of quasi-omni printed dipole antennas printed in
opposite directions with reference to the RF IC, wherein the pair
of quasi-omni printed dipole antennas together provide spectrum
coverage of 360 degrees.
14. A quasi-omni printed dipole antenna comprising: two dipole
strips printed on a first substrate layer of a printed circuit
board (PCB); a transmission line printed on the first substrate
layer and between the two dipole strips; and a cavity directly
under the two dipole strips, wherein a perimeter of the cavity is
substantially the same as the perimeter of the two dipole strips
and a depth of the cavity is a number of substrate layers of the
PCB under the first substrate layer.
15. The antenna of claim 14, wherein spectrum coverage of the
quasi-omni printed dipole antenna is 180 degrees.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional
application No. 61/086,924 filed on Aug. 7, 2008, the contents of
which are herein incorporated by reference.
TECHNICAL FIELD
[0002] The present invention relates generally to radio frequency
integrated circuits, and particularly to connecting radio frequency
integrated circuits to millimeter wave antennas.
BACKGROUND OF THE INVENTION
[0003] The 60 Giga Hertz (GHz) band is an unlicensed band which
features a large amount of bandwidth allowing a very high volume of
information to be transmitted wirelessly. As a result, multiple
applications, that require transmission of a large amount of data,
can be developed to allow wireless communication around the 60 GHz
band. Examples for such applications include, but are not limited
to, a wireless high definition TV (HDTV), a wireless docking
station, a wireless Gigabit Ethernet, and many others.
[0004] In order to facilitate such applications there is a need to
develop integrated circuits (ICs), such as amplifiers, mixers, and
radio frequency (RF) analog circuits that operate in the 60 GHz
frequency band. Such circuits should be fabricated as a chip that
can be assembled on a printed circuit board (PCB). In addition,
there is a need to develop low-cost and high-performance millimeter
wave antennas to enable the integration of 60 GHz communication
applications in consumer electronics products.
[0005] One of the requirements of millimeter wave antennas is
minimal energy loss, to achieve maximum power antenna gain. Most of
the energy is lost due to the connection between an antenna and an
integrated circuit (IC), or chip, processing the RF signals to be
transmitted or received. With the aim to minimize energy loss,
prior art approaches suggest mounting millimeter wave antennas
directly on the surface of a PCB using, for example, a surface
mount technology (SMT). A SMT is a method for constructing
electronic circuits in which the components are mounted directly
onto the surface of a PCB.
[0006] One type of millimeter wave antenna suitable for the 60 GHz
band is the on-chip dipole antenna. An exemplary diagram of on-chip
dipole antenna 100 is shown in FIG. 1. The antenna 100 includes two
printed dipole strips 110 and an electrical transmission line 120
that acts as an unbalanced-to-balanced transformer between a feed
coaxial line 130 and the two printed dipole strips 110. The length
of the dipole strips is approximately a 1/4 wavelength. The
electrical line 120 and the dipole strips 110 are printed on the
same plane. In addition, the antenna 100 does not provide spectrum
coverage of 360 degrees.
[0007] The on-chip dipole antenna 100 is not feasible for
commercial uses due to its inefficiency. For example, experiments
show that the simulated antenna radiation efficiency is
approximately 16 percent. In addition, the maximum transmit power
of the antenna at 60 GHz is approximately -20 dBi. This is due to
the substrate and connection losses.
[0008] Another technique for mounting an antenna onto a PCB is
known as the low temperature co-fired ceramic (LTCC) process. The
LTCC is a complex process that allows on-chip connection to an
antenna. Particularly, a unit produced using this process is a
compact multilayer three-dimensional design allowing other
components to be combined within a miniature surface-mount package,
and eliminating the need for many external components. However, the
LTCC process is very costly, and therefore is not feasible for
commercial uses.
[0009] It would be therefore advantageous to provide an efficient
and low-cost solution for connecting millimeter wave antennas and
ICs onto PCBs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Embodiments of the invention are particularly pointed out
and distinctly claimed at the conclusion of the specification in
the claims. The foregoing and other objects, features and
advantages of exemplary embodiments of the invention will be
apparent from the following detailed description taken in
conjunction with the accompanying drawings.
[0011] FIG. 1 is a diagram of an on-chip dipole antenna.
[0012] FIG. 2 is a three-dimensional diagram illustrating the
assembly of a millimeter antenna on a PCB in accordance with an
embodiment of the present invention.
[0013] FIG. 3 is a flowchart describing a method for mounting a RF
IC and a millimeter wave antenna onto a PCB in accordance with an
embodiment of the invention.
[0014] FIGS. 4A and 4B are graphs showing radiation patterns of
quasi-omni printed antennas.
[0015] FIG. 5 is a cross-section diagram illustrating the structure
of a quasi-omni printed antenna constructed in accordance with an
embodiment of the invention.
[0016] FIG. 6 is a schematic diagram of a PCB constructed to
include a pair of quasi-omni printed antennas connected to a RF
IC.
SUMMARY OF THE INVENTION
[0017] Certain embodiments of the invention include a printed
circuit board (PCB) assembled to include at least one millimeter
wave antenna and a radio frequency integrated circuit (RF IC). The
PCB comprises a square-shaped cavity in the PCB, wherein one of the
edges of the cavity is substantially parallel to connecting pins of
the at least one millimeter wave antenna; a RF IC placed in the
cavity, wherein one side of the RF IC including RF pads is
substantially at the edge of the cavity that is substantially
parallel to the connecting pins; and traces connecting the RF pads
and the connecting pins, wherein the connection between the at
least one millimeter wave antenna and the RF IC shortens the length
of the traces.
[0018] Certain embodiments of the invention also include method for
mounting a millimeter wave antenna and a radio frequency integrated
circuit (RF IC) onto a printed circuit board (PCB). The method
comprises forming a square-shaped cavity in the PCB wherein one of
edges of the cavity is substantially parallel to connecting pins of
the millimeter wave antenna, wherein the millimeter wave antenna is
printed on a first substrate layer of the PCB; placing the RF IC in
the cavity by positioning one side of the RF IC including RF pads
substantially at the edge of the cavity that is substantially
parallel to the connecting pins; and bonding the RF pads and the
connecting pins.
[0019] Certain embodiments of the invention further include a
quasi-omni printed dipole antenna. The antenna comprises two dipole
strips printed on a first substrate layer of a printed circuit
board (PCB); a transmission line printed on the first substrate
layer and between the two dipole strips; and a cavity directly
under the two dipole strips, wherein a perimeter of the cavity is
substantially the same as the perimeter of the two dipole strips
and a depth of the cavity is a number of substrate layers of the
PCB under the first substrate layer.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The subject matter that is regarded as the invention is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
objects, features and advantages of the invention will be apparent
from the following detailed description taken in conjunction with
the accompanying drawings.
[0021] Certain embodiments of the invention include a method for
mounting a millimeter wave antenna and a RF IC onto a PCB. Certain
embodiments of the method reduce the energy lost on the connection
between these two circuits. Other embodiments of the invention
include a quasi-omnidirectional (omni) millimeter wave antenna, and
a method of manufacture. Certain embodiments of the invention
enable a mass production of low-cost and high performance RF
devices that can be utilized in millimeter wave bands including,
but not limited to, 60 GHz and 77 GHz.
[0022] FIG. 2 shows a three-dimensional diagram illustrating the
assembly of a RF IC 210 and a millimeter wave antenna 220 on a PCB
230. The RF IC 210 may be either a receiver or transmitter and the
antenna 220 may be either a receive-antenna or a transmit-antenna.
In certain implementation, a typical PCB 230 may include at least
two RF ICs acting as a receiver and transmitter as well as receive
and transmit antennas. Without departing from the scope of the
invention, a connection of a single RF IC 210 to a single antenna
220 will be described herein.
[0023] In accordance with certain principles of the invention the
length of the traces 240 (or wires) connecting the RF IC 210 to the
antenna 220 is minimized, thereby minimizing the energy lost on
this connection. With this aim, the RF IC 210 is placed in a cavity
trimmed down in the PCB 230. The depth of the cavity is
substantially the same as the height of the RF IC 210, thus the
upper surface of the RF IC 210 is at the same level as the surface
of the PCB 230. Specifically, as the PCB 230 is multilayer, the
depth of the cavity is one or more substrate layers being cut out
the PCB 230. In addition, in order to ensure the possible shortest
traces 240, the RF IC 210 is placed in the cavity in such way that
the IC's 210 side having RF pads 250 is located at an edge of the
cavity. In accordance with an embodiment of the invention the RF IC
210 is in a form of a die (i.e., unpackaged IC).
[0024] FIG. 3 shows a non-limiting flowchart 300 describing the
method for mounting a millimeter wave antenna and a RF IC onto a
PCB implemented in accordance with an embodiment of the invention.
The method allows shortening the lengths of wires connecting the RF
IC to a millimeter wave antenna. Certain specific embodiments of
this method minimize the energy loss and increase the antenna gain.
At S310, a square-shaped cavity is cut into the substrate layers of
the PCB in a way that one of the edges of the cavity is
substantially parallel to the connecting pins (e.g., pins 240)
leading to the antenna. The depth of the cavity is substantially
the same as the height of RF IC and its perimeter is approximately
the same as of the RF IC. At S320 the RF IC is placed in the cavity
in a way that the side including the RF pads (e.g., pads 250) is
located at the edge of the cavity. At S330, the RF pads on the RF
IC and the pins leading to the antenna are bonded, thereby forming
a connection between the RF IC and antenna.
[0025] Another embodiment of the invention includes a quasi-omni
printed antenna that provides 180 degrees beamwidth (on the A-z
plane). An exemplary radiation pattern on the A-z plane of the
disclosed quasi-omni printed antenna is shown in FIG. 4A.
Simulations show that the antenna gain of the quasi-omni printed
antenna is 5dBi. The quasi-omni printed antenna is constructed by
printing a dipole pointing to a certain direction on a first
substrate layer of the PCB and forming a cavity under the printed
dipole.
[0026] FIG. 5 shows a cross-section diagram of a quasi-omni printed
antenna 500 constructed in accordance with an embodiment of the
invention. Two dipole strips 501 and an electrical transmission
line 502 of the antenna 500 are printed on a first substrate layer
of a PCB 510. The length of the dipole strips 501 is approximately
a 1/4 wavelength. A cavity 520 is created by cutting out all
substrate layers of the PCB 510 under the antenna 500. In the
diagram shown in FIG. 5, the PCB 510 includes 5 layers, 4 of which
are cut out. The size of the cavity 520 is substantially the same
as the size of the antenna 500. It should be noted that the cavity
520 is not the cavity mentioned above with reference the embodiment
of mounting a RF IC onto a PCB. The antenna 500 operates in
millimeter wave bands including, but not limiting to, 60 GHz and 77
GHz.
[0027] In accordance with another embodiment of the invention two
quasi-omni printed antennas 500 are used to achieve spectrum
coverage of 360 degrees in transmission or reception of radio
signals. As illustrated in FIG. 6, on a PCB 600 a RF IC 610 is
mounted. The RF IC 610 is connected to two quasi-omni printed
antennas 500-A and 500-B, pointing to different directions. The RF
IC 610 is connected to the antennas 500-A and 500-B as described in
detail above. The RF IC 610 includes a switch (not shown) adapted
to switch between the antenna 500-A or 500-B according to desirable
transmission/reception direction, thereby providing coverage of 360
degrees. An exemplary radiation pattern on the A-z plane achieved
using two quasi-omni printed antennas is shown in FIG. 4B.
[0028] While the present invention has been described at some
length and with some particularity with respect to the several
described embodiments, it is not intended that it should be limited
to any such particulars or embodiments or any particular
embodiment, but it is to be construed with references to the
appended claims so as to provide the broadest possible
interpretation of such claims in view of the prior art and,
therefore, to effectively encompass the intended scope of the
invention. Furthermore, the foregoing describes the invention in
terms of embodiments foreseen by the inventor for which an enabling
description was available, notwithstanding that insubstantial
modifications of the invention, not presently foreseen, may
nonetheless represent equivalents thereto. The word "substantially"
is used based on the nature of the invention, in order to
accommodate the minor variations that may be appropriate as
understood by one of ordinary skill in the art to describe the
invention with precision appropriate to the technology.
* * * * *