Patent US5548840A successfully refreshed from Google Patents.
US5548840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Balanced mixer circuit with improved linearity
Assignee: Motorola Solutions Inc
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Filing: 1994-03-28
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Granted: 1996-08-20
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Expires: 2014-03-28
Abstract
Abstract A balanced mixer circuit includes a first balanced input (RF(+) and RF(-)), a second balanced input (LO(+) and LO(-), and a balanced output (OUT+and OUT-). The balanced mixer circuit also includes a mixer for mixing a first signal with a second signal. The mixer further includes a first input and second input which is coupled to the second input of the balanced mixer circuit. The balanced mixer circuit also includes a pair of couplers for coupling the first input of the mixer circuit to the first input of the mixer. Each of the pair of couplers includes a feedback circuit having a current source and an active component for improving the performance of the balanced mixer circuit.
Inventors
- 👤 Joseph P. Heck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:44
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/26; H03; H03D; H03D7/00; H03D7/14; H03D7/1425; H03D7/1433; H03D7/1458; H03D7/1491
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
157 words
A balanced mixer circuit having a pair of differential inputs (RF+, RF-), the balanced mixer circuit comprising: balanced mixer means having outputs (Out+, Out-) for differentially mixing a first differential radio frequency signal, received at a first pair of differential inputs (RF'+, RF'-), with a second differential local oscillator signal received at a second pair of differential inputs (LO+, LO-) to produce a differential output signal; and coupler means for coupling the pair of differential inputs (RF+, RF-) of the balanced mixer circuit to the first pair of differential inputs (RF'+, RF'-) of the balanced mixer means, the coupler means including a pair of transconductance amplifiers differentially coupled to each other, each amplifier having a feedback circuit containing a current source and an active component coupled to each of the pair of transconductance amplifiers for forcing the amplifiers to operate more linearly in order to improve intermodulation performance of the balanced mixer without degrading the noise figure.
Claim 2
Dependent Claim
157 words
A balanced mixer circuit having a pair of differential inputs (RF+, RF-), the balanced mixer circuit comprising: balanced mixer means having outputs (Out+, Out-) for differentially mixing a first differential radio frequency signal, received at a first pair of differential inputs (RF'+, RF'-), with a second differential local oscillator signal received at a second pair of differential inputs (LO+, LO-) to produce a differential output signal; and coupler means for coupling the pair of differential inputs (RF+, RF-) of the balanced mixer circuit to the first pair of differential inputs (RF'+, RF'-) of the balanced mixer means, the coupler means including a pair of transconductance amplifiers differentially coupled to each other, each amplifier having a feedback circuit containing a current source and an active component coupled to each of the pair of transconductance amplifiers for forcing the amplifiers to operate more linearly in order to improve intermodulation performance of the balanced mixer without degrading the noise figure.
Claim 3
Dependent Claim
20 words
The balanced mixer circuit of claim 1, further including a biasing means for biasing the coupler means and mixer means.
Claim 4
Dependent Claim
25 words
The balanced mixer circuit of claim 1, wherein the balanced mixer means includes a switching means for switching the first signal at a pre-determined rate.
Claim 5
Dependent Claim
15 words
The balanced mixer circuit of claim 1, wherein the coupler means includes a transconductance amplifier.
Claim 6
Dependent Claim
157 words
A balanced mixer circuit having outputs (out+, out-) for differentially mixing a first differential radio frequency signal, received at a first pair of differential inputs (RF+, RF-), with a second differential local oscillator signal received at a second pair of differential inputs (Lo+, Lo-)to produce an output signal (Out+, Out-), the balanced mixer circuit comprising: a mixer means having a plurality of switches for switching the first differential radio frequency signal at the rate of the second differential local oscillator signal; a pair of transconductance amplifiers differentially coupled to each other for coupling the first pair of differential inputs (RF+, RF-) of the balanced mixer circuit to the mixer means; and a pair of feedback circuits each having a current source and an active component coupled to each of the pair of transconductance amplifiers for forcing the amplifiers to operate more linearly in order to improve intermodulation performance of the balanced mixer without degrading the noise figure.
Claim 7
Dependent Claim
157 words
A balanced mixer circuit having outputs (out+, out-) for differentially mixing a first differential radio frequency signal, received at a first pair of differential inputs (RF+, RF-), with a second differential local oscillator signal received at a second pair of differential inputs (Lo+, Lo-)to produce an output signal (Out+, Out-), the balanced mixer circuit comprising: a mixer means having a plurality of switches for switching the first differential radio frequency signal at the rate of the second differential local oscillator signal; a pair of transconductance amplifiers differentially coupled to each other for coupling the first pair of differential inputs (RF+, RF-) of the balanced mixer circuit to the mixer means; and a pair of feedback circuits each having a current source and an active component coupled to each of the pair of transconductance amplifiers for forcing the amplifiers to operate more linearly in order to improve intermodulation performance of the balanced mixer without degrading the noise figure.
Claim 8
Dependent Claim
14 words
The mixer circuit of claim 5, wherein the mixer means comprises balanced mixer means.
Claim 9
Dependent Claim
15 words
The mixer circuit of claim 5, wherein the balanced mixer means includes a doubly-balanced mixer.
Claim 10
Dependent Claim
15 words
The mixer circuit of claim 5, wherein the balanced mixer means includes a triply-balanced mixer.
Claim 11
Dependent Claim
21 words
The balanced mixer circuit of claim 5, further including a biasing means for biasing the transconductance amplifiers and the mixer means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-08-20 | 2000-02-19 | 2000-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-20 | 2004-02-19 | 2004-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-20 | 2008-02-19 | 2008-08-20 | $7700.00 | Window Closed / Lapsed |