Communications receiver using multi-band transmit blocking filters

• US 10,454,516 B2
• Filed: 07/09/2018
• Issued: 10/22/2019
• Est. Priority Date: 01/20/2017
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Resonant Inc. (Murata Manufacturing Co Limited)
• Inventors: Guyette, Andy, Levesque, Chris
• Primary Examiner(s): Sandiford, Devan A
• Application Number:
  US16/030,502
• Publication Number:
  US 20180331711A1
• Time in Patent Office: 470 Days
• CPC Class Codes: H04B 1/401 for selecting or indicating operating mode
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04L 25/00 Baseband systems
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

Communications receivers and devices are disclosed. A communications receiver includes a low noise amplifier; a multi-band transmit blocking filter having a first port connected to an output of the low noise amplifier, and an RF analog-to-digital converter having an input connected to a second port of the multi-band transmit blocking filter. The multi-band transmit filter passes the receive frequencies of a group of two or more LTE bands, where a first receive frequency range of a first band in the group and a second receive frequency range of a second band in the group are disjoint and not subsets of a receive frequency range of a third band in the group, and attenuates the transmit frequencies of at least some bands in the group by at least twenty dB.

Claims

1. A dual-passband filter having a first passband, a second passband higher in frequency than the first passband, a first stopband lower in frequency than the first passband, and a second stopband between the first and second passbands, the dual pass-band filter comprising:

a first surface acoustic wave (SAW) band-pass filter in parallel with a second SAW band-pass filter, wherein;

the first SAW band-pass filter passes the first passband,

the second SAW band-pass filter passes the second passband, and

the second stop band attenuates, by at least 20 dB, transmit frequencies of at least one LTE band.

2. The dual-passband filter of claim 1, wherein

a relative phase of the transfer functions of the first and second SAW band-pass filters is controlled such that an insertion loss of the dual-passband filter is greater than insertion losses of both the first and second SAW band-pass filters in isolation for at least one frequency in the at least one of the first and second stop bands.

3. The dual-passband filter of claim 1, wherein

the first passband includes receive frequencies of at least a first LTE band;

the second passband includes receive frequencies of at least a second LTE band; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of the first and second LTE bands.

4. The dual-passband filter of claim 3, wherein

the first SAW band-pass filter is configured to pass receive frequencies of LTE band 30;

the second SAW band-pass filter is configured to pass receive frequencies of LTE band 7; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of LTE bands 7 and 30.

5. The dual-passband filter of claim 1, wherein

the first passband includes receive frequencies of two or more first LTE bands;

the second passband includes receive frequencies of at least one second LTE bands; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of all of the first and second LTE bands.

6. The dual-passband filter of claim 5, wherein

the first SAW band-pass filter is configured to pass receive frequencies of LTE bands 20, 28A, 28B, and 68;

the second SAW band-pass filter is configured to pass receive frequencies of LTE band 8; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of LTE bands 8, 20, 28A, 28B, and 68.

7. The dual-passband filter of claim 1, wherein

the first passband includes receive frequencies of two or more first LTE bands;

the second passband includes receive frequencies of two or more second LTE bands; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of all of the first and second LTE bands.

8. The dual-passband filter of claim 7, wherein

the first SAW band-pass filter is configured to pass receive frequencies of LTE bands 12, 13, 14, and 17;

the second SAW band-pass filter is configured to pass receive frequencies of LTE bands 5, 6, 18, 19, and 26; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of LTE bands 5, 6, 12, 13, 14, 17, 18, 19, and 26.

9. The dual-passband filter of claim 7, wherein

the first SAW band-pass filter is configured to pass receive frequencies of LTE bands 3 and 9;

the second SAW band-pass filter is configured to pass receive frequencies of LTE bands 1, 4, 10, 23, 65, and 66; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of LTE bands 1, 3, 4, 9, 10, 23, 65, and 66.

10. A communications receiver comprising:

a low noise amplifier;

a dual-passband filter having a first port connected to an output of the low noise amplifier; and

an RF analog-to-digital converter having an input connected to a second port of the dual-passband filter, wherein

the dual-passband filter has a first passband, a second passband higher in frequency than the first passband, a first stopband lower in frequency than the first passband, and a second stopband between the first and second passbands, and

the dual pass-band filter comprises;

a first surface acoustic wave (SAW) band-pass filter in parallel with a second SAW band-pass filter, the first SAW band-pass filter passing the first passband and the second SAW band-pass filter passing the second passband.

11. The communications receiver of claim 10, wherein

a relative phase of the transfer functions of the first and second SAW band-pass filters in at least one of the first and second stop bands is controlled such that an insertion loss of the dual-passband filter is greater than insertion losses of both the first and second SAW band-pass filters in isolation for at least one frequency in the at least one of the first and second stop bands.

12. The communications receiver of claim 10, wherein

the first passband includes receive frequencies of at least a first LTE band;

the second passband includes receive frequencies of at least a second LTE band; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of the first and second LTE bands.

13. The communications receiver of claim 12, wherein

the first SAW band-pass filter is configured to pass receive frequencies of LTE band 30;

the second SAW band-pass filter is configured to pass receive frequencies of LTE band 7; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of LTE bands 7 and 30.

14. The communications receiver of claim 10, wherein

the first passband includes receive frequencies of two or more first LTE bands;

the second passband includes receive frequencies of at least one second LTE bands; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of all of the first and second LTE bands.

15. The communications receiver of claim 14, wherein

the first SAW band-pass filter is configured to pass receive frequencies of LTE bands 20, 28A, 28B, and 68;

the second SAW band-pass filter is configured to pass receive frequencies of LTE band 8; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of LTE bands 8, 20, 28A, 28B, and 68.

16. The communications receiver of claim 10, wherein

the first passband includes receive frequencies of two or more first LTE bands;

the second passband includes receive frequencies of two or more second LTE bands; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of all of the first and second LTE bands.

17. The communications receiver of claim 16, wherein

the first SAW band-pass filter is configured to pass receive frequencies of LTE bands 12, 13, 14, and 17;

the second SAW band-pass filter is configured to pass receive frequencies of LTE bands 5, 6, 18, 19, and 26; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of LTE bands 5, 6, 12, 13, 14, 17, 18, 19, and 26.

18. The communications receiver of claim 16, wherein

the first SAW band-pass filter is configured to pass receive frequencies of LTE bands 3 and 9;

the second SAW band-pass filter is configured to pass receive frequencies of LTE bands 1, 4, 10, 23, 65, and 66; and

the dual-passband filter is configured to attenuate, by at least twenty dB, transmit frequencies of LTE bands 1, 3, 4, 9, 10, 23, 65, and 66.