Circuit for suppressing signals adjacent to a passband

Patent metadata

Field	Value
Publication number	US-10491193-B2
Application number	US-201715592319-A
Country	US
Kind code	B2
Filing date	May 11, 2017
Priority date	May 13, 2016
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A circuit having a power amplifier port, an antenna port, and a ladder network coupled between the power amplifier and antenna ports is disclosed. The ladder network includes a proximal series acoustic resonator coupled to the power amplifier port, a distal series acoustic resonator coupled to the antenna port, and at least one series acoustic resonator coupled between the proximal series acoustic resonator and the distal series acoustic resonator. A first shunt acoustic resonator is coupled between a fixed voltage node and the proximal series acoustic resonator and the at least one series acoustic resonator. A second shunt acoustic resonator is coupled between the fixed voltage node and a second node to which the at least one series acoustic resonator is also coupled. A first inductor is coupled in parallel with the proximal series acoustic resonator to create notches below and above a passband of the ladder network.

First claim

What is claimed is:

1. A circuit comprising a power amplifier port, an antenna port, and a ladder network coupled between the power amplifier port and the antenna port wherein the ladder network comprises:
a power amplifier having an output terminal coupled to the power amplifier port;
a proximal series acoustic resonator coupled to the output terminal through the power amplifier port;
a distal series acoustic resonator coupled to the antenna port, wherein no inductor is coupled in parallel with the distal series acoustic resonator;
at least one series acoustic resonator coupled between the proximal series acoustic resonator and the distal series acoustic resonator;
a grounding inductor coupled to a fixed voltage node;
a first shunt acoustic resonator coupled between the fixed voltage node and a first node shared by the proximal series acoustic resonator and the at least one series acoustic resonator;
a proximal shunt acoustic resonator coupled in series with the grounding inductor between the power amplifier port and the fixed voltage node;
a second shunt acoustic resonator coupled between the fixed voltage node and a second node to which the at least one series acoustic resonator is also coupled;
a first notch inductor coupled in parallel with the proximal series acoustic resonator; and
a second notch inductor coupled in parallel with the at least one series acoustic resonator adjacent to the proximal series acoustic resonator.

2. The circuit of claim 1 wherein the fixed voltage node is at ground potential.

3. The circuit of claim 1 wherein an antenna is coupled to the antenna port.

4. The circuit of claim 1 wherein the proximal series acoustic resonator, the at least one series acoustic resonator, the distal series acoustic resonator, the first shunt acoustic resonator, and the second shunt acoustic resonator are surface acoustic wave resonators.

5. The circuit of claim 1 wherein the proximal series acoustic resonator, the at least one series acoustic resonator, the distal series acoustic resonator, the first shunt acoustic resonator, and the second shunt acoustic resonator are bulk acoustic wave resonators.

6. The circuit of claim 1 wherein the proximal series acoustic resonator, the at least one series acoustic resonator, the distal series acoustic resonator, the first shunt acoustic resonator, and the second shunt acoustic resonator are thin-film bulk acoustic wave resonators.

7. The circuit of claim 1 wherein the proximal series acoustic resonator, the at least one series acoustic resonator, the distal series acoustic resonator, the first shunt acoustic resonator, and the second shunt acoustic resonator are solidly mounted (acoustic) resonators.

8. The circuit of claim 1 wherein the first notch inductor provides an anti-resonance resonance frequency with a Butterworth Van-Dyke model (BVD) static capacitance of the proximal series acoustic resonator.

9. The circuit of claim 8 wherein an inductance of the first notch inductor combined with the BVD static capacitance creates a notch below a passband of the ladder network.

10. The circuit of claim 9 wherein the inductance of the first notch inductor combined with the BVD static capacitance creates the notch within a global positioning system (GPS) band.

11. The circuit of claim 9 wherein the inductance of the first notch inductor reduces the capacitive effect of the BVD static capacitance of the proximal series acoustic resonator, upshifting an anti-resonance frequency and creating a notch above the passband of the ladder network.

12. The circuit of claim 9 wherein the inductance of the first notch inductor reduces the capacitive effect of the BVD static capacitance of the proximal series acoustic resonator, upshifting the anti-resonance frequency and creating a notch within a counter-band of a transmit band passed by the ladder network.

13. The circuit of claim 9 wherein the inductance of the first notch inductor reduces the capacitive effect of the BVD static capacitance of the proximal series acoustic resonator, upshifting the anti-resonance frequency and creating a 2.4 GHz ISM/wireless fidelity (WiFi) band.

14. The circuit of claim 1 wherein the ladder network is integrated into a single die having a first pair of external pins for coupling the first notch inductor in parallel with the proximal series acoustic resonator, which is coupled to the power amplifier port.

15. The circuit of claim 1 wherein the ladder network and the first notch inductor are integrated into a single die.

16. The circuit of claim 14 further including a second pair of external pins for the second notch inductor coupled in parallel with the at least one series acoustic resonator closest to and coupled to the power amplifier port.

17. The circuit of claim 1 wherein the ladder network, the first notch inductor, and the second notch inductor are integrated into a single die.

18. The circuit of claim 1 wherein the ladder network and the first notch inductor are integrated into a single die having a pair of external coupling terminals to couple the second notch inductor that is external to the die in parallel with the at least one series acoustic resonator closest coupled to the power amplifier port.

19. The circuit of claim 1 wherein the ladder network and the second notch inductor are integrated into a single die having a pair of external coupling terminals to couple the first notch inductor that is external to the die in parallel with the proximal series acoustic resonator.

20. The circuit of claim 1 wherein out-of-band suppression of unwanted frequencies between 500 MHz and 4 GHz is at least −35 dB.

21. The circuit of claim 1 wherein transmit signal return loss for a passband between 1920 MHz and 1980 MHz is no more than −15 dB.

22. The circuit of claim 1 wherein a notch impedance of the circuit for a GPS band between 1559 MHz and 1626.5 MHz provides at least −45 dB of unwanted transmit signal suppression at the antenna port.

23. The circuit of claim 1 wherein impedance provided by the circuit for an industrial scientific and medical (ISM) band between 2.4 GHz and 2.5 GHz provides at least −45 dB of unwanted transmit signal suppression at the antenna port.

24. The circuit of claim 1 wherein impedance provided by the circuit for a counter-band of a transmit band is at least −50 dB.

25. The circuit of claim 24 wherein insertion loss provided by the circuit for the transmit band is between −3 dB and 0 dB.

Assignees

• Qorvo Us Inc

Inventors

• Cihangir Aykut
• Link Andreas

Classifications

• H03F1/565

  using inductive elements · CPC title

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title

• H03F3/19

  with semiconductor devices only · CPC title

• H03H9/542

  including passive elements (H03H9/545 takes precedence) · CPC title

• H03F2200/171

  A filter circuit coupled to the output of an amplifier · CPC title