US6704559B1
Expired / Lapsed
US
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Broadband RF mixer with improved intermodulation suppression
Assignee: Murata Manufacturing Co Ltd
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Filing: 2000-09-18
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Granted: 2004-03-09
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Expires: 2020-09-18
Abstract
Abstract An RF mixer circuit having reduced intermodulation products includes a cascode transconductance amplifier including a first transistor having a control electrode connected to receive an input signal and serially connected with a second transistor having a control electrode connected to receive a bias potential. A balanced mixer is coupled to the second transistor by a first inductive element for receiving an amplified input signal current, and receiving a local oscillator signal and producing an output signal with an intermediate frequency related to the frequencies of the amplifier input signal and the local oscillator. A feedback circuit is provided from the second transistor to the control electrode of the first transistor including a resistor serially connected with a capacitor, whereby the feedback circuit compensates for signal phase shift by the inductive element.
Inventors
- 👤 Hans Hageraats
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:11
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/26; H04B1/28; H03; H03D; H03D7/00; H03D7/14; H03D7/1425; H03D7/1433; H03D7/1441; H03D7/1458; H03D7/1491
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
146 words
An RF mixer circuit having reduced intermodulation products comprising: a) a cascode transconductance amplifier with inductive emitter degeneration including a first transistor having a control electrode connected to receive an input RF signal and serially connected with a second transistor having a control electrode connected to receive a bias potential; b) a balanced mixer coupled to the second transistor by a first inductive element for receiving an amplified input signal and receiving a signal from a local oscillator and producing an output signal with an intermediate frequency related to the frequencies of the amplifier input signal and the local oscillator, and c) a feedback circuit from the second transistor to the control electrode of the first transistor including a resistor serially connected with a capacitor, whereby the feedback circuit compensates for signal phase shift by the inductive element so that the IM3 products are cancelled out.
Claim 2
Dependent Claim
146 words
An RF mixer circuit having reduced intermodulation products comprising: a) a cascode transconductance amplifier with inductive emitter degeneration including a first transistor having a control electrode connected to receive an input RF signal and serially connected with a second transistor having a control electrode connected to receive a bias potential; b) a balanced mixer coupled to the second transistor by a first inductive element for receiving an amplified input signal and receiving a signal from a local oscillator and producing an output signal with an intermediate frequency related to the frequencies of the amplifier input signal and the local oscillator, and c) a feedback circuit from the second transistor to the control electrode of the first transistor including a resistor serially connected with a capacitor, whereby the feedback circuit compensates for signal phase shift by the inductive element so that the IM3 products are cancelled out.
Claim 3
Dependent Claim
42 words
The RF mixer circuit as defined by claim 1 wherein the feedback circuit components are selected as a function of input impedance of the mixer circuit, inductance of the inductive element, and the maximum frequency (f T ) of the cascode amplifier.
Claim 4
Dependent Claim
28 words
The RF mixer circuit as defined by claim 1 and further including a capacitive element coupling the control electrode of the second transistor to a circuit ground potential.
Claim 5
Dependent Claim
25 words
The RF mixer circuit as defined by claim 3 and further including a second inductive element coupling the first transistor to the circuit ground potential.
Claim 6
Dependent Claim
20 words
The RF mixer circuit as defined by claim 4 wherein the first transistor and the second transistor are bipolar transistors.
Claim 7
Dependent Claim
66 words
The RF mixer circuit as defined by claim 5 wherein the input signal has a frequency on the order of 2 GHz, the feedback circuit has a resistor on the order of 500 ohms and a capacitor on the order of 300 fF, the first inductive element is on the order of 8 nH, and the second inductive element is on the order of 1.5 nH.
Claim 8
Dependent Claim
65 words
The RF mixer circuit as defined by claim 5 wherein the input signal has a frequency on the order of 1 GHz, the feedback circuit has resistor on the order of 1000 ohms and a capacitor on the order of 600 fF, the first inductive element is on the order of 16 nH, and the second inductive element is on the order of 3 nH.
Claim 9
Dependent Claim
21 words
The RF mixer circuit as defined by claim 4 wherein the first transistor and the second transistor are field effect transistors.
Claim 10
Dependent Claim
18 words
The RF mixer circuit as defined by claim 8 wherein the first transistor and second transistor are MOSFETs.
Claim 11
Dependent Claim
31 words
The RF mixer circuit as defined by claim 1 wherein the mixer comprises a pair of transistors in parallel driven by an in-phase and 180° out of phase local oscillator signals.
Claim 12
Dependent Claim
74 words
In an RF mixer circuit in which a cascode transconductance amplifier with inductive emitter degeneration receives an input signal and drives a mixer stage controlled by a local oscillator, circuitry for suppressing intermodulation components comprising an inductive element coupling the cascode transconductance amplifier to the mixer stage, and a cascode transconductance amplifier feedback loop comprising a resistor serially connected with a capacitor, the feedback loop compensating for phase shift imparted by the inductive element.
Claim 13
Dependent Claim
74 words
In an RF mixer circuit in which a cascode transconductance amplifier with inductive emitter degeneration receives an input signal and drives a mixer stage controlled by a local oscillator, circuitry for suppressing intermodulation components comprising an inductive element coupling the cascode transconductance amplifier to the mixer stage, and a cascode transconductance amplifier feedback loop comprising a resistor serially connected with a capacitor, the feedback loop compensating for phase shift imparted by the inductive element.
Claim 14
Dependent Claim
60 words
Circuitry as defined by claim 11 wherein the cascode transconductance amplifier includes a first transistor having a control electrode connected to receive an input signal and serially connected with a second transistor having a control electrode connected to receive a bias potential; the feedback loop coupling the output of the second transistor to the control electrode of the first transistor.
Claim 15
Independent Claim
155 words
A method of RF mixing to provide reduced intermodulation products comprising: a) providing a cascode transconductance amplifier with inductive emitter degeneration including a first transistor having a control electrode connected to receive an input RF signal and serially connected with a second transistor having a control electrode connected to receive a bias potential; b) providing a balanced mixer coupled to the second transistor by a first inductive element for receiving an amplified input signal and receiving a signal from a local oscillator and producing an output signal with an intermediate frequency related to the frequencies of the amplifier input signal and the local oscillator, and c) feeding back a signal from the second transistor to the control electrode of the first transistor through a feedback circuit including a resistor serially connected with a capacitor, whereby the feedback circuit compensates for signal phase shift by the inductive element so that the IM3 products are cancelled out.
Claim 16
Independent Claim
155 words
A method of RF mixing to provide reduced intermodulation products comprising: a) providing a cascode transconductance amplifier with inductive emitter degeneration including a first transistor having a control electrode connected to receive an input RF signal and serially connected with a second transistor having a control electrode connected to receive a bias potential; b) providing a balanced mixer coupled to the second transistor by a first inductive element for receiving an amplified input signal and receiving a signal from a local oscillator and producing an output signal with an intermediate frequency related to the frequencies of the amplifier input signal and the local oscillator, and c) feeding back a signal from the second transistor to the control electrode of the first transistor through a feedback circuit including a resistor serially connected with a capacitor, whereby the feedback circuit compensates for signal phase shift by the inductive element so that the IM3 products are cancelled out.
Claim 17
Dependent Claim
42 words
The method as defined by claim 13 wherein the components of the feedback circuit are selected as a function of input impedance of the mixer circuit, inductance of the inductive element, and the maximum frequency (f T ) of the cascode amplifier.
Claim 18
Dependent Claim
26 words
The method as defined by claim 13 further including providing a capacitive element coupling the control electrode of the second transistor to a circuit ground potential.
Claim 19
Dependent Claim
22 words
The method of claim 15 and further including providing a second inductive element coupling the first transistor to the circuit ground potential.
Claim 20
Dependent Claim
16 words
The method of claim 16 wherein the first transistor and the second transistor are bipolar transistors.
Claim 21
Dependent Claim
62 words
The method of claim 17 wherein the input signal has a frequency on the order of 2 GHz, the feedback circuit has a resistor on the order of 500 ohms and a capacitor on the order of 300 fF, the first inductive element is on the order of 8 nH, and the second inductive element is on the order of 1.5 nH.
Claim 22
Dependent Claim
61 words
The method of claim 17 wherein the input signal has a frequency on the order of 1 GHz, the feedback circuit has resistor on the order of 1000 ohms and a capacitor on the order of 600 fF, the first inductive element is on the order of 16 nH, and the second inductive element is on the order of 3 nH.
Claim 23
Dependent Claim
17 words
The method of claim 16 wherein the first transistor and the second transistor are field effect transistors.
Claim 24
Dependent Claim
16 words
The method as defined by claim 20 wherein the first transistor and second transistor are MOSFETs.
Claim 25
Dependent Claim
27 words
The method as defined by claim 13 wherein the mixer comprises a pair of transistors in parallel driven by an in-phase and 180° phase local oscillator signals.
Claim 26
Dependent Claim
78 words
For use in an RF mixer in which a cascode transconductance amplifier with inductive emitter degeneration receives an input signal and drives a mixer stage controlled by a local oscillator, a method of suppressing intermodulation components comprising providing an inductive element coupling the cascode transconductance amplifier to the mixer stage, and providing a cascode transconductance amplifier feedback loop comprising a resistor serially connected with a capacitor, the feedback loop compensating for phase shift imparted by the inductive element.
Claim 27
Dependent Claim
78 words
For use in an RF mixer in which a cascode transconductance amplifier with inductive emitter degeneration receives an input signal and drives a mixer stage controlled by a local oscillator, a method of suppressing intermodulation components comprising providing an inductive element coupling the cascode transconductance amplifier to the mixer stage, and providing a cascode transconductance amplifier feedback loop comprising a resistor serially connected with a capacitor, the feedback loop compensating for phase shift imparted by the inductive element.
Claim 28
Dependent Claim
59 words
The method of claim 23 wherein the cascode transconductance amplifier includes a first transistor having a control electrode connected to receive an input signal and serially connected with a second transistor having a control electrode connected to receive a bias potential; the feedback loop coupling the output of the second transistor to the control electrode of the first transistor.
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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) | 2007-03-09 | 2007-09-08 | 2008-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-03-09 | 2011-09-08 | 2012-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-03-09 | 2015-09-08 | 2016-03-09 | $7700.00 | Window Closed / Lapsed |