US6351502B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
RF front-end with multistage stepdown filtering architecture
Assignee: Qualcomm Inc
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Filing: 2000-01-13
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Granted: 2002-02-26
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Expires: 2020-01-13
Abstract
Abstract A radio-frequency (RF) front-end is described. In one embodiment, the RF front-end comprises a low noise amplifier (LNA), a first mixer and an I/Q quadrature mixer. The LNA amplifies a received signal at a carrier frequency, the LNA having inductive loads. The first mixer is coupled to the low noise amplifier and mixes an amplified received signal with a first local oscillator (LO) signal to down convert the amplified received signal to an intermediate frequency (IF). The first mixer has inductive loads. The first frequency is related to the carrier frequency such that an image channel associated with the carrier and the LO frequency is outside the bandwidth of the inductive loads of the LNA. The I/Q quadrature mixer stage has a second mixer and a third mixer coupled to the first mixer. The I/Q quadrature mixer converts the amplified received signal at the IF to I and Q signals using a second LO signal related to the first LO signal.
Inventors
- 👤 Masoud Zargari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:43
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/26; H04B1/28; H03; H03D; H03D7/00; H03D7/14; H03D7/1425; H03D7/1441; H03D7/1483; H03D7/16; H03D7/165; H03D2200/00; H03D2200/0001; H03D2200/0023
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
146 words
A radio-frequency (RF) front-end comprising: a low noise amplifier (LNA) to amplify a received signal at a carrier frequency, the LNA having inductive loads; a first mixer, coupled to the low noise amplifier, to mix an amplified received signal with a first local oscillator (LO) signal to down convert the amplified received signal to an intermediate frequency (IF), the first mixer having inductive loads, wherein the IF is related to the carrier frequency such that an image channel associated with the carrier and the frequency of the LO signal is outside the bandwidth of the inductive loads of the LNA; an I/Q quadrature mixer stage having a second mixer and a third mixer coupled to the first mixer, the I/Q quadrature mixer converting the amplified received signal at the IF to I and Q signals using a second LO signal related to the first LO signal.
Claim 2
Dependent Claim
146 words
A radio-frequency (RF) front-end comprising: a low noise amplifier (LNA) to amplify a received signal at a carrier frequency, the LNA having inductive loads; a first mixer, coupled to the low noise amplifier, to mix an amplified received signal with a first local oscillator (LO) signal to down convert the amplified received signal to an intermediate frequency (IF), the first mixer having inductive loads, wherein the IF is related to the carrier frequency such that an image channel associated with the carrier and the frequency of the LO signal is outside the bandwidth of the inductive loads of the LNA; an I/Q quadrature mixer stage having a second mixer and a third mixer coupled to the first mixer, the I/Q quadrature mixer converting the amplified received signal at the IF to I and Q signals using a second LO signal related to the first LO signal.
Claim 3
Dependent Claim
20 words
The RF front-end defined in claim 1 wherein the IF is no greater than 80 percent of the carrier frequency.
Claim 4
Dependent Claim
21 words
The RF front-end defined in claim 1 wherein the carrier frequency is 5.3 GHz and the first frequency is 4.24 GHz.
Claim 5
Dependent Claim
27 words
The RF front-end defined in claim 1 further comprising a divide-by-four to divide the first local oscillator signal by four to generate the second local oscillator signal.
Claim 6
Dependent Claim
17 words
The RF front-end defined in claim 1 wherein the LNA is capacitively coupled to the first mixer.
Claim 7
Dependent Claim
20 words
The RF front-end defined in claim 1 wherein the LNA is coupled to the first mixer using a coupling capacitor.
Claim 8
Dependent Claim
20 words
The RF front-end defined in claim 1 wherein the first mixer is capacitively coupled to the I/Q quadature mixer stage.
Claim 9
Dependent Claim
24 words
The RF front-end defined in claim 1 wherein the first mixer is capacitively coupled to the I/Q quadature mixer stage using a coupling capacitor.
Claim 10
Dependent Claim
136 words
A radio-frequency (RF) front-end comprising: a low noise amplifier (LNA) to amplify a received signal at a carrier frequency, the LNA having inductive loads; a first mixer coupled to the low noise amplifier, the first mixer to mix an amplified received signal with a first local oscillator signal to down convert the amplified received signal to an intermediate frequency (IF), the first mixer having inductive loads, wherein the IF is related to the carrier frequency such that the IF is no greater than 80 percent of the carrier frequency; and an I/Q quadrature mixer stage having a second mixer and a third mixer coupled to the first mixer, the I/Q quadrature mixer converting the amplified received signal at the IF to I and Q signals using a second local oscillator related to the first local oscillator.
Claim 11
Dependent Claim
136 words
A radio-frequency (RF) front-end comprising: a low noise amplifier (LNA) to amplify a received signal at a carrier frequency, the LNA having inductive loads; a first mixer coupled to the low noise amplifier, the first mixer to mix an amplified received signal with a first local oscillator signal to down convert the amplified received signal to an intermediate frequency (IF), the first mixer having inductive loads, wherein the IF is related to the carrier frequency such that the IF is no greater than 80 percent of the carrier frequency; and an I/Q quadrature mixer stage having a second mixer and a third mixer coupled to the first mixer, the I/Q quadrature mixer converting the amplified received signal at the IF to I and Q signals using a second local oscillator related to the first local oscillator.
Claim 12
Dependent Claim
20 words
The RF front-end defined in claim 9 wherein the carrier frequency is 5.3 GHz and the IF is 4.24 GHz.
Claim 13
Dependent Claim
27 words
The RF front-end defined in claim 9 further comprising a divide-by-four to divide the first local oscillator signal by four to generate the second local oscillator signal.
Claim 14
Dependent Claim
20 words
The RF front-end defined in claim 9 wherein the LNA is coupled to the first mixer using a coupling capacitor.
Claim 15
Dependent Claim
24 words
The RF front-end defined in claim 9 wherein the first mixer is capacitively coupled to the I/Q quadature mixer stage using a coupling capacitor.
Claim 16
Dependent Claim
175 words
A communication device comprising: a radio frequency (RF) front end comprising a low noise amplifier (LNA) to amplify a received signal at a carrier frequency, the LNA having inductive loads, a first mixer, coupled to the low noise amplifier, to mix an amplified received signal with a first local oscillator (LO) signal to down convert the amplified received signal to an intermediate frequency (IF), the first mixer having inductive loads, wherein the IF is related to the carrier frequency such that an image channel associated with the carrier and the frequency of the LO signal is outside the bandwidth of the inductive loads of the LNA, an I/Q quadrature mixer stage having a second mixer and a third mixer coupled to the first mixer, the I/Q quadrature mixer converting the amplified received signal at the IF to I and Q signals using a second LO signal related to the first LO signal; a filter coupled to the RF front end; an analog-to-digital converter (ADC) coupled to the filter; and a processor coupled to the ADC.
Claim 17
Dependent Claim
175 words
A communication device comprising: a radio frequency (RF) front end comprising a low noise amplifier (LNA) to amplify a received signal at a carrier frequency, the LNA having inductive loads, a first mixer, coupled to the low noise amplifier, to mix an amplified received signal with a first local oscillator (LO) signal to down convert the amplified received signal to an intermediate frequency (IF), the first mixer having inductive loads, wherein the IF is related to the carrier frequency such that an image channel associated with the carrier and the frequency of the LO signal is outside the bandwidth of the inductive loads of the LNA, an I/Q quadrature mixer stage having a second mixer and a third mixer coupled to the first mixer, the I/Q quadrature mixer converting the amplified received signal at the IF to I and Q signals using a second LO signal related to the first LO signal; a filter coupled to the RF front end; an analog-to-digital converter (ADC) coupled to the filter; and a processor coupled to the ADC.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-02-25 | 2005-08-27 | 2006-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-02-25 | 2009-08-27 | 2010-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-02-25 | 2013-08-27 | 2014-02-26 | $7700.00 | Window Closed / Lapsed |