SAW-LESS RECEIVER WITH RF FREQUENCY TRANSLATED BPF

• US 20110299632A1
• Filed: 03/30/2011
• Published: 12/08/2011
• Est. Priority Date: 06/03/2010
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Mirzaei, Ahmad, Darabi, Hooman
• Granted Patent: US 8,655,299 B2
• Time in Patent Office: Days
• US Class Current: 375/340
• CPC Class Codes: H03F 1/083 in transistor amplifiers H03F1/10 - H03F1/22 take precedence
• CPC Class Codes: H03F 3/45179 using MOSFET transistors as the active amplifying circuit H03F3/45278 takes precedence
• CPC Class Codes: H03H 19/002 N-path filters
• CPC Class Codes: H04B 1/006 using switches for selecting the desired band H04B1/0057 takes precedence
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 1/1638 Special circuits to enhance selectivity of receivers not otherwise provided for resonant circuits H03H
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04B 1/401 for selecting or indicating operating mode

Abstract

A SAW-less receiver includes an FEM interface module, an RF to IF receiver section, and a receiver IF to baseband section. The RF to IF receiver section includes a frequency translated bandpass filter (FTBPF), an LNA, and a mixing section. The FTBPF includes a switching network and a plurality of baseband impedances. The switching network is operable to couple the plurality of baseband impedances to the FEM interface in accordance with a plurality of phase-offset RF clock signals to RF bandpass filter the inbound RF signal. The LNA amplifies the filtered inbound RF signal and the mixing section mixes the amplified inbound RF signal with a local oscillation to produce an inbound IF signal. The receiver IF to baseband section converts the inbound IF signal into one or more inbound symbol streams.

Claims

1. A surface acoustic wave (SAW)-less receiver comprises:

a front end module (FEM) interface module operable to receive an inbound radio frequency (RF) signal;

an RF to intermediate frequency (IF) receiver section that includes;

a frequency translated bandpass filter (FTBPF) that includes;

a switching network; and

a plurality of baseband impedances forming a baseband filter response, wherein the switching network is operable to couple the plurality of baseband impedances to the FEM interface in accordance with a plurality of phase-offset RF clock signals to RF bandpass filter the inbound RF signal to produce a filtered inbound RF signal;

a low noise amplifier module (LNA) operable to amplify the filtered inbound RF signal to produce an amplified inbound RF signal; and

a mixing section operable to mix the amplified inbound RF signal with a local oscillation to produce an inbound IF signal; and

a receiver IF to baseband section operable to convert the inbound IF signal into one or more inbound symbol streams.

2. The SAW-less receiver of claim 1, wherein the FEM interface module comprises:

a transformer; and

a tunable capacitor network C1 operably coupled to a secondary of the transformer and to filter a received inbound RF signal to produce the inbound RF signal.

3. The SAW-less receiver of claim 1 further comprises:

a front end module operable to isolate the inbound RF signal from an undesired RF signal.

4. The SAW-less receiver of claim 1, wherein the receiver IF to BB section comprises:

a mixing section operable to mix the inbound IF signal with a second local oscillation to produce I and Q mixed signals; and

a combining &

filtering section operable to;

combine the I and Q mixed signals to produce a combined signal; and

filter the combined signal to produce the one or more inbound symbol streams.

5. The SAW-less receiver of claim 1 further comprises:

a clock generator operable to generate the plurality of phase-offset clock signals, wherein the switching network periodically couples the plurality of baseband impedances to the FEM interface module and the LNA based on the plurality of phase-offset clock signals, and wherein a rate of the plurality of phase-offset clock signals corresponds to a frequency of the inbound RF signal.

6. The SAW-less receiver of claim 1, wherein the mixing section comprises:

a mixing module operable to;

convert the amplified inbound RF signal into an in-phase (I) signal component and a quadrature (Q) signal component;

mix the I signal component with an I signal component of a local oscillation to produce an I mixed signal;

mix the Q signal component with a Q signal component of the local oscillation to produce a Q mixed signal; and

a filter module operable to filter the I and Q mixed signals to produce the inbound IF signal.

7. The SAW-less receiver of claim 1, wherein the switching network is further operable to:

couple first and third baseband impedances of the plurality of baseband impedances in a first coupling pattern to filter the inbound RF signal during a first one of the plurality of phase-offset RF clock signals;

couple second and fourth baseband impedances of the plurality of baseband impedances in a second coupling pattern to filter the inbound RF signal during a second one of the plurality of phase-offset RF clock signals;

couple the first and third baseband impedances in an inverse first coupling pattern to filter the inbound RF signal during a third one of the plurality of phase-offset RF clock signals; and

couple the second and fourth baseband impedances in an inverse second coupling pattern to filter the inbound RF signal during a fourth one of the plurality of phase-offset RF clock signals.

8. The SAW-less receiver of claim 7, wherein a baseband impedance of the plurality of baseband impedances comprises at least one of:

a capacitor;

a variable capacitor;

a switched capacitor filter;

a switch capacitor resistance; and

a complex impedance.

9. The SAW-less receiver of claim 1, wherein the FTBPF further comprises:

a control module operable to receive a control signal, wherein the control signal provides control information to adjust one or more of;

the quality factor of the baseband filter response, gain of the baseband filter response, bandwidth of the baseband filter response, and an attenuation slope of the baseband filter response.

10. A surface acoustic wave (SAW)-less receiver comprises:

a front end module (FEM) interface module operable to receive an inbound radio frequency (RF) signal;

an RF to intermediate frequency (IF) receiver section that includes;

an RF frequency translated bandpass filter (FTBPF) that includes;

a first switching network; and

a first plurality of baseband impedances forming a first baseband filter response, wherein the first switching network is operable to couple the plurality of baseband impedances to the FEM interface in accordance with a plurality of phase-offset RF clock signals to RF bandpass filter the inbound RF signal to produce a filtered inbound RF signal;

a low noise amplifier module (LNA) operable to amplify the filtered inbound RF signal to produce an amplified inbound RF signal; and

a mixing section operable to mix the amplified inbound RF signal with a local oscillation to produce an inbound IF signal;

an IF FTBPF that includes;

a second switching network; and

a second plurality of baseband impedances forming a second baseband filter response, wherein the second switching network is operable to couple the second plurality of baseband impedances to the mixing section in accordance with a plurality of phase-offset IF clock signals to IF bandpass filter the inbound IF signal to produce a filtered inbound IF signal; and

a receiver IF to baseband section operable to convert the filtered inbound IF signal into one or more inbound symbol streams.

11. The SAW-less receiver of claim 10, wherein the FEM interface module comprises:

a transformer; and

a tunable capacitor network C1 operably coupled to a secondary of the transformer and to filter a received inbound RF signal to produce the inbound RF signal.

12. The SAW-less receiver of claim 10 further comprises:

a front end module operable to isolate the inbound RF signal from an undesired RF signal.

13. The SAW-less receiver of claim 10, wherein the receiver IF to BB section comprises:

a mixing section operable to mix the inbound IF signal with a second local oscillation to produce I and Q mixed signals; and

a combining &

filtering section operable to;

combine the I and Q mixed signals to produce a combined signal; and

filter the combined signal to produce the one or more inbound symbol streams.

14. The SAW-less receiver of claim 10 further comprises:

a clock generator operable to;

generate the first plurality of phase-offset clock signals, wherein the first switching network periodically couples the first plurality of baseband impedances to the FEM interface module and the LNA based on the first plurality of phase-offset clock signals, and wherein a rate of the first plurality of phase-offset clock signals corresponds to a frequency of the inbound RF signal; and

generate the second plurality of phase-offset clock signals, wherein the second switching network periodically couples the second plurality of baseband impedances to the mixing module based on the second plurality of phase-offset clock signals, and wherein a rate of the second plurality of phase-offset clock signals corresponds to a frequency of the inbound IF signal.

15. The SAW-less receiver of claim 10, wherein the mixing section comprises:

a mixing module operable to;

convert the amplified inbound RF signal into an in-phase (I) signal component and a quadrature (Q) signal component;

mix the I signal component with an I signal component of a local oscillation to produce an I mixed signal;

mix the Q signal component with a Q signal component of the local oscillation to produce a Q mixed signal; and

a filter module operable to filter the I and Q mixed signals to produce the inbound IF signal.

16. The SAW-less receiver of claim 10, wherein the first switching network is further operable to:

couple first and third baseband impedances of the first plurality of baseband impedances in a first coupling pattern to filter the inbound RF signal during a first one of the plurality of phase-offset RF clock signals;

couple second and fourth baseband impedances of the first plurality of baseband impedances in a second coupling pattern to filter the inbound RF signal during a second one of the plurality of phase-offset RF clock signals;

couple the first and third baseband impedances in an inverse first coupling pattern to filter the inbound RF signal during a third one of the plurality of phase-offset RF clock signals; and

couple the second and fourth baseband impedances in an inverse second coupling pattern to filter the inbound RF signal during a fourth one of the plurality of phase-offset RF clock signals.

17. The SAW-less receiver of claim 10, wherein the second switching network is further operable to:

couple first and third baseband impedances of the second plurality of baseband impedances in a first coupling pattern to filter the inbound IF signal during a first one of the plurality of phase-offset IF clock signals;

couple second and fourth baseband impedances of the second plurality of baseband impedances in a second coupling pattern to filter the inbound IF signal during a second one of the plurality of phase-offset IF clock signals;

couple the first and third baseband impedances in an inverse first coupling pattern to filter the inbound IF signal during a third one of the plurality of phase-offset IF clock signals; and

couple the second and fourth baseband impedances in an inverse second coupling pattern to filter the inbound IF signal during a fourth one of the plurality of phase-offset IF clock signals.

18. The SAW-less receiver of claim 10, wherein a baseband impedance of the first or second plurality of baseband impedances comprises at least one of:

a capacitor;

a variable capacitor;

a switched capacitor filter;

a switch capacitor resistance; and

a complex impedance.

19. The SAW-less receiver of claim 10, wherein the RF FTBPF further comprises:

a control module operable to receive a control signal, wherein the control signal provides control information to adjust one or more of;

the quality factor of the baseband filter response, gain of the baseband filter response, bandwidth of the baseband filter response, and an attenuation slope of the first baseband filter response.

20. The SAW-less receiver of claim 10, wherein the IF FTBPF further comprises:

a control module operable to receive a control signal, wherein the control signal provides control information to adjust one or more of;

the quality factor of the baseband filter response, gain of the baseband filter response, bandwidth of the baseband filter response, and an attenuation slope of the second baseband filter response.