US4896374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broadband monolithic balanced mixer apparatus
Assignee: Siemens AG
•
Filing: 1988-12-09
•
Granted: 1990-01-23
•
Expires: 2008-12-09
Abstract
Abstract A broadband monolithic balanced mixer employs a unidirectional active 180° hybrid. The hybrid is fabricated utilizing two active signal splitters, two all pass phase shifting networks and two active signal combiners. The all pass networks provide a controlled phase response while the absolute phase of the network varies with frequency whereby the frequency difference between the two networks remains constant at 180° over a very broad frequency range. Because the phase varies with frequency, the source and load impedance are rendered equal and resistive. Thus the above-described apparatus employs a common source FET with feedback for the signal splitter and a common gate FET for the combiner. Matching networks are used at all four ports of the active hybrid to achieve the desired match over the desired frequency ranges. The outputs of the hybrid are applied to suitable mixer circuits including FET or diode devices.
Inventors
- 👤 Raymond M. Waugh
- 👤 Tzu-Hung Chen
- 👤 Mahesh Kumar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:26
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/14; H03D7/1425; H03D7/1441; H03D7/1408; H03D7/1483; H03D2200/00; H03D2200/0041; H03D2200/0043
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
312 words
A broadband monolithic balanced mixer apparatus for use within the microwave frequency ranges, comprising: an active hybrid means having one input adapted to receive an RF signal and another input adapted to receive a local oscillator (LO) signal to provide at first and second outputs a combined LO and RF signal, said active hybrid means having a first active signal splitter having an input coupled to said one input for receiving said RF signal and having first and second outputs, a second active signal splitter having an input coupled to said another input for receiving said LO signal, said second splitter having first and second outputs, a first active signal combiner having a first input coupled to said first output of said first signal splitter and having a second input and an output, a second active signal combiner having a first input coupled to said second output of said first splitter and having a second input and an output, a first all pass network having an input and an output terminal, with said input coupled to said first output of said second splitter and with said output coupled to said second input of said first combiner, a second all pass network having an input and an output, with the input of said second all pass network coupled to said second output of said second splitter and with the output of said second all pass network coupled to the second input of said second combiner, wherein the output of said first and second combiners each provide an RF/LO signal of a different phase with respect to one another, and mixing means coupled to said outputs of said first and second combiners to provide at an output an IF signal being of a frequency equal to the difference between said RF and LO signal frequencies and substantially free of said RF and LO signals.
Claim 2
Dependent Claim
312 words
A broadband monolithic balanced mixer apparatus for use within the microwave frequency ranges, comprising: an active hybrid means having one input adapted to receive an RF signal and another input adapted to receive a local oscillator (LO) signal to provide at first and second outputs a combined LO and RF signal, said active hybrid means having a first active signal splitter having an input coupled to said one input for receiving said RF signal and having first and second outputs, a second active signal splitter having an input coupled to said another input for receiving said LO signal, said second splitter having first and second outputs, a first active signal combiner having a first input coupled to said first output of said first signal splitter and having a second input and an output, a second active signal combiner having a first input coupled to said second output of said first splitter and having a second input and an output, a first all pass network having an input and an output terminal, with said input coupled to said first output of said second splitter and with said output coupled to said second input of said first combiner, a second all pass network having an input and an output, with the input of said second all pass network coupled to said second output of said second splitter and with the output of said second all pass network coupled to the second input of said second combiner, wherein the output of said first and second combiners each provide an RF/LO signal of a different phase with respect to one another, and mixing means coupled to said outputs of said first and second combiners to provide at an output an IF signal being of a frequency equal to the difference between said RF and LO signal frequencies and substantially free of said RF and LO signals.
Claim 3
Dependent Claim
51 words
The broadband monolithic balanced mixer according to claim 1 wherein said first all pass network provides a phase shift of +90° over a broadband microwave range, with said second all pass network providing a phase shift of -90° over said range, with said different phase at said combiner outputs being 180°.
Claim 4
Dependent Claim
92 words
The broadband monolithic balanced mixer according to claim 1 wherein said first and second signal splitters each comprise: a FET device having dual output electrodes as dual drain or source electrodes, a second output electrode as a single drain or source electrode and a gate input electrode adapted to receive said RF or LO signal, with both of said dual electrodes coupled to said gate electrode via an impedance network, with a first electrode of said dual electrodes indicative of said first output and the second electrode indicative of said second output.
Claim 5
Dependent Claim
47 words
The broadband monolithic balanced mixer according to claim 3 further including a first matching network coupled to said gate electrode, a second matching network coupled to said first electrode of said dual pair and a third matching network coupled to said second electrode of said dual pair.
Claim 6
Dependent Claim
52 words
The broadband monolithic mixer according to claim 1 wherein said first and second active signal combiners each include, a FET having dual input electrodes as source or drain electrodes for receiving first and second input signals, a grounded gate electrode, and a source or drain output electrode indicative of said combiner output.
Claim 7
Dependent Claim
21 words
The broadband monolithic mixer according to claim 5 further including a matching network coupled to said output electrode of said combiner.
Claim 8
Dependent Claim
77 words
The broadband monolithic mixer according to claim 4 wherein said impedance network includes a first resistor having one terminal connected to said first electrode of said dual electrodes and the other terminal connected to one terminal of a capacitor having the other terminal connected to said gate electrode, with a second resistor connected at one terminal to said other one of said dual electrodes and the other terminal connected to said other terminal of said first resistor.
Claim 9
Dependent Claim
36 words
The broadband monolithic mixer according to claim 1 wherein said first and second all pass networks each provide a controlled phase response wherein the phase difference between the two networks remains constant over said broadband range.
Claim 10
Dependent Claim
83 words
The broadband monolithic mixer according to claim 1 wherein said mixing means comprises, a first microwave diode having the anode coupled to the output of said second combiner, a second microwave diode having the cathode coupled to the output of said first combiner, with the cathode of said first diode connected to the anode of said second diode to form an output port, a low pass filter having an input coupled to said output port and an output for providing said IF signal.
Claim 11
Dependent Claim
184 words
The broadband monolithic mixer according to claim 1 wherein said mixing means includes, a first FET having a gate electrode coupled to said output of said first combiner and having a grounded source or drain electrode, with the non-grounded source or drain electrode indicative of a first output, a second FET having a gate electrode coupled to said output of said second combiner and having a grounded source or drain electrode, with the non-grounded source or drain electrode indicative of a second output, a first low pass filter having an input coupled to said first output of said first FET and having an output, a second low pass filter having an input coupled to said second output of said second FET and having an output, an active 180° combiner having one input coupled to the output of said first low pass filter and a second input coupled to the output of said second low pass filter, said active 180° combiner having a first output for providing a first IF signal and a second output for providing a second IF signal of a different phase.
Claim 12
Dependent Claim
127 words
The broadband monolithic balanced mixer according to claim 10, wherein said active 180° combiner includes, first and second FET devices arranged in a differential amplifier configuration with the gate electrode of said first FET coupled to the output of said first low pass filter and with the gate electrode of said second FET coupled to the output of said second low pass filter, with the source or drain electrode of said first FET providing said first output and with the source or drain electrode of said second FET providing said second output, with said source or drain electrodes of said FETs not providing an output connected together, and constant current means coupled to said connected electrodes to provide a ground return for said first and second FETs.
Claim 13
Dependent Claim
44 words
The broadband monolithic balanced mixer according to claim 11 wherein said constant current means includes a third FET having the source or drain electrode connected to said connected together electrodes and having the other electrode as source or drain connected to the gate electrode.
Claim 14
Dependent Claim
14 words
The broadband monolithic mixer according to claim 3 wherein said FET is a MESFET.
Claim 15
Dependent Claim
14 words
The broadband monolithic mixer according to claim 5 wherein said FET is a MESFET.
Claim 16
Dependent Claim
16 words
The broadband monolithic mixer according to claim 10 wherein said first and second FETs are MESFETs.
Claim 17
Dependent Claim
19 words
The broadband monolithic mixer according to claim 9 wherein said first and second microwave diodes are Schottky barrier diodes.
Claim 18
Dependent Claim
17 words
The broadband monolithic mixer according to claim 11 wherein said first and second FET devices are MOSFETs.
Claim 19
Dependent Claim
15 words
The broadband monolithic mixer according to claim 12 wherein said third FET is a MOSFET.
Claim 20
Dependent Claim
37 words
The broadband monolithic mixer according to claim 11 further including a first matching network coupled to the gate electrode of said first FET and a second matching network coupled to the gate electrode of said second FET.
Claim 21
Dependent Claim
25 words
The broadband monolithic mixer according to claim 11 further including mixer means DC coupled to said first and second outputs of said active 180° combiner.
References Cited (Backward Citations)
US4224572A
Cited
US4605902A
Cited
US4731875A
Cited
US4751744A
Cited
US4677691A
Cited
US4817201A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-22 | 1993-07-24 | 1994-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-22 | 1997-07-24 | 1998-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-22 | 2001-07-24 | 2002-01-23 | $7700.00 | Window Closed / Lapsed |