Wafer probe with built in RF frequency conversion module

Details Wafer probe with built in RF frequency conversion module Wafer probe with built in RF frequency conversion module

1998-11-09

2001-01-02

Metjahic, Safet (Department: 2858)

Electricity: measuring and testing

Fault detecting in electric circuits and of electric components

Of individual circuit component or element

C324S537000

Utility Patent

active

06169410

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to components for a vector network analyzer (VNA) and wafer probe which may be used to test integrated circuits manufactured for an automobile collision avoidance radar.
2. Description of the Related Art
Recently, automobile manufacturers, have provided collision avoidance radar systems in a limited number of vehicle models. Collision avoidance radar systems have also recently been made available for purchase by consumers for installation on trucks or automobiles. An example of such a system is the Eaton® VORAD® Collision Warning System available from Eaton VORAD Technologies, L.L.C., of San Diego, Calif.
Collision avoidance radar systems currently available operate by transmitting and receiving signals using an antenna located in the front grill area of a vehicle. The collision avoidance radar determines from a delay before a return signal is received, or from a frequency shift in a signal received, a distance an object causing the return signal is located from the vehicle and how fast the object is traveling relative to the vehicle.
Collision avoidance radar systems typically operate within a narrow frequency band. In the United States, the Federal Communications Commission (FCC) has allocated the frequency range of 76-77 GHz for collision avoidance radars.
A VNA is typically used with an attached wafer probe to test microwave integrated circuit components manufactured for a collision avoidance radar. A traditional VNA is an expensive system designed to operate over a wide range of frequencies.
FIG. 1
shows a block diagram of typical components included in a VNA. As shown, the VNA includes signal sources
100
-
101
, a test set
102
, test modules
104
-
105
, and a VNA controller
108
.
A typical signal source which may be used for the LO signal source
100
and RF signal source
102
for a VNA is the Anritsu model 68037B, manufactured by Anritsu Company of Morgan Hill Calif. The 68037B signal source operates over a 2-20 GHz frequency range and provides power up to +17 dBm. The frequencies for the signal sources
100
-
101
are controlled by VNA controller
108
through signals over a general purpose interface bus (GPIB). An example of a VNA controller is the 37100A manufactured by Anritsu Company.
The LO signal from signal source
100
and the RF signal from signal source
101
are provided to a test set
102
, such as the 3735A test set manufactured by Anritsu Company. Components included in the test set are shown in FIG.
2
. The test includes a transfer switch
200
which selectively provides the RF drive signal from the RF signal source
101
to either the RF port
1
which connects to RF module
104
, or to the RF port
2
which connects to the RF module
105
. The transfer switch
200
is controlled by a signal received from the VNA controller
108
. A power divider
202
provides the LO signal from the LO signal source
100
to the LO ports of the RF modules
104
and
105
. The test set
102
further includes a power supply
204
and a printed circuit board (PCB) assembly
206
. The power supply
204
converts a standard 115V AC signal to 12V and 15V DC signals. The PCB assembly
206
, then provides further voltage regulation and distributes 12V and 15V signals to the RF modules
104
and
105
and forwards the transfer switch control signal to the transfer switch
200
. The test set
102
further forwards the test IF and reference IF signals from the RF modules
104
and
105
to the VNA controller
108
as S-Parameter signals a
1
, a
2
, b
1
, and b
2
.
Components for RF modules
104
and
105
are shown in FIG.
3
. An example of the RF module shown is the Anritsu 3741A-X millimeter wave module. The RF module of
FIG. 3
contains multipliers
300
and
302
to enable a maximum 20 GHz output from the RF signal source
101
to be multiplied up to 80 GHz to provide coverage of the 76-77 GHz bandwidth for collision avoidance radar systems. Amplifier
304
serves to boost the input signal to the multiplier, while the output of multiplier
300
is amplified by amplifier
306
. Amplifiers
304
and
306
receive power from the +12V output of the test set
102
. Although the multipliers
300
and
302
are shown as times two (×2) devices, the multiplication factor is altered in test sets designed to cover frequency bands other than the 76-77 GHz bandwidth for collision avoidance radars.
An RF test signal is provided from multiplier
302
through dual directional coupler
308
to a test port as a test signal. The dual directional coupler
308
serves to provide both the test signal and a reference signal for analysis. The reference signal is provided from a first directional coupler in the dual coupler
308
which couples an incident signal provided from the RF signal source
101
through multipliers
300
and
302
and amplifiers
304
and
306
to a harmonic mixer
310
. The test signal is received from a second coupler in dual coupler
308
which couples a transmitted or reflected signal from the test port to a harmonic mixer
312
. The test signal results from reflections from a test device connected to the test port which will occur if an impedance mismatch exists. When a mismatch occurs, some of the test signal incident at the port will travel into the test device, and some will be reflected back to the test port. The transfer switch
200
of the test set
102
may provide the test signal through another RF module to measure parameters of a two port test device. With a test signal provided from a second RF module in a two port device, the portion of the signal that travels through the test device goes to the test port of the first RF module for measurement.
The harmonic mixers
310
and
312
mix the RF signals from the dual directional coupler
308
with the LO signal provided to the mixers through amplifier
313
and power divider
314
to downconvert the RF test and reference signals to 270 MHZ intermediate frequency (IF) signals TEST IF and REF IF. The amplifier
313
is a limiting amplifier used to keep the LO power at a fixed level into the harmonic mixers. The amplifier
320
provides the TEST IF signal from mixer
312
, while the amplifier
322
provides the REF IF signal from the mixer
310
. Amplifiers
313
,
320
, and
322
receive power from the +15V output of the test set
102
. The TEST IF and REF IF signals are provided from the RF modules
104
-
105
to the VNA controller
108
via the test set
102
. The TEST IF signal carries embedded magnitude and phase information relative to the REF IF signal.
An example of the VNA controller is the Anritsu 37100A. A typical VNA controller includes synchronous detectors, a digital signal processor or microprocessor, and a display. The synchronous detectors convert the TEST IF and REF IF signals to digital signal data. The VNA processor controlled by embedded firmware coupled with system software, manipulates this digital data. Resultant S-Parameter data characterizing the test device is then presented on the display, and can also be output to a printer or plotter, or routed to the rear panel external GPIB interface.
A wafer probe is an accessory which may be attached to test ports of a VNA enabling the VNA to be used to measure components for a wafer. Measurements on a wafer are performed before wafer circuits are separated or diced.
SUMMARY OF THE INVENTION
The present invention was developed with recognition that with a potential increase in demand for collision avoidance radar systems, it will be desirable to have a test system operating over a narrow bandwidth of the collision avoidance radar system to reduce test equipment cost.
The present invention was further developed with recognition that millimeter microwave integrated circuits (MMICs) used in collision avoidance radar systems are similar to components required in the RF module of a VNA, and the MMICs will operate over the narrow collision avoidance radar frequency range of 76-77 GHz. The present invention was further developed with recognitio

Affiliated with

Also associated with

Rating

Wafer probe with built in RF frequency conversion module does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Wafer probe with built in RF frequency conversion module, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wafer probe with built in RF frequency conversion module will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2482798