RADIO FREQUENCY FRONT END MODULE WITH HIGH BAND SELECTIVITY

• US 20150118977A1
• Filed: 05/28/2014
• Published: 04/30/2015
• Est. Priority Date: 10/30/2013
• Status: Active Grant

• Current Assignee: NETGEAR, Inc.
• Original Assignee: NETGEAR, Inc.
• Inventors: EMMANUEL, Joseph Amalan Arul
• Granted Patent: US 9,838,069 B2
• Time in Patent Office: Days
• US Class Current: 455/83
• CPC Class Codes: H04B 1/48 in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter H04B1/46 takes precedence
• CPC Class Codes: H04B 2001/485 inhibiting unwanted transmission

Abstract

A radio frequency front end module is provided for a high power capability and a high signal band selectivity. The front end module includes an external filter and an integrated circuit coupled with the external filter via two external filter leads. The integrated circuit includes a transmit-receive switch, a power amplifier and a low noise amplifier. The transmit-receive switch alternates between coupling an antenna port to a transmit port and coupling the antenna port to a receive port. The power amplifier amplifies a modulated radio frequency signal. The low noise amplifier amplifies a received radio frequency signal when the antenna port is coupled to the receive port. The external filter can be replaced to adapt to various requirements of signal frequency bands, without the need of modifying the layout of the integrated circuit.

Claims

1. A radio frequency front end module for transmitting and receiving radio frequency signals, the front end module comprising:

an external filter; and

an integrated circuit coupled with the external filter via two external filter leads, the integrated circuit including;

a transmit-receive switch having a transmit port, a receive port and an antenna port, the transmit-receive switch during operation alternates between coupling the antenna port to the transmit port and coupling the antenna port to the receive port;

a power amplifier configured to amplify a modulated radio frequency signal, the transmit-receive switch outputs the amplified modulated radio frequency signal when the antenna port is coupled to the transmit port;

a low noise amplifier configured to amplify a received radio frequency signal when the antenna port is coupled to the receive port; and

the two external filter leads coupling the external filter between the low noise amplifier and the receive port of the transmit-receive switch.

2. The front end module of claim 1, wherein the integrated circuit further includes:

a low pass filter coupled between the power amplifier and the transmit port of the transmit-receive switch, the low pass filter configured to pass low-frequency signals and attenuates signals with frequencies higher than a cutoff frequency.

3. The front end module of claim 1, wherein the external filter is a band pass filter configured to pass signals at frequencies within a specific pass band and attenuates signals at other frequencies outside the specific pass band.

4. The front end module of claim 3, wherein the pass band of the external filter matches a frequency band of radio frequency signals that the front end module is designed to process.

5. The front end module of claim 1, wherein the power amplifier is a multistage amplifier.

6. The front end module of claim 1, wherein the power amplifier is configured to output a radio frequency single having a power of more than 100 mW.

7. The front end module of claim 1, wherein the power amplifier is configured to output a radio frequency single having a power of more than 500 mW.

8. The front end module of claim 1, wherein the dimensions of the integrated circuit is less than or equals to 7×

5 mm².

9. The front end module of claim 1, further comprising:

a power lead to supply electrical power to the integrated circuit for operation; and

wherein the integrated circuit configured to operate at two different voltages.

10. The front end module of claim 3, wherein the external filter is a tunable band pass filter configured to adjust the pass band dynamically during operation of the front end module.

11. The front end module of claim 1, further comprising:

a plurality of external filters including the external filter;

a control lead configured to supply a control signal to dynamically couple one external filter of the plurality of external filters to the integrated circuit during operation of the front end module.

12. The front end module of claim 1, wherein the external filter is a discrete electronic component.

13. The front end module of claim 1, further comprising:

a control signal lead configured to supply a control signal to turn off the power amplifier, or to bypass the low noise amplifier.

14. A wireless networking device for transmitting and receiving radio frequency signals, the device comprising:

an antenna configured to transmit an output radio frequency signal and to receive an input radio frequency signal;

an front end module, the front end module including an integrated circuit to transmit the output radio frequency signal to the antenna and to receive the input radio frequency signal from the antenna under a time-division multiplexing framework, the integrated circuit amplifying the output radio frequency signal and the input radio frequency signal; and

a radio signal component configured to modulate a carrier wave to construct the output radio frequency signal, and to demodulate the input radio frequency signal to extract an information-bearing signal.

15. The device of claim 14, wherein the front end module further includes band pass filter coupled to the integrated circuit, the band pass filter configured to pass signals at frequencies within a specific pass band of the output and input radio frequency signals and attenuates signals at other frequencies outside the specific pass band.

16. The device of claim 14, wherein the integrated circuit includes:

a transmit-receive switch having a transmit port, a receive port and an antenna port, the transmit-receive switch during operation alternates between coupling the antenna port to the transmit port and coupling the antenna port to the receive port;

a power amplifier configured to amplify the output radio frequency signal, when the antenna port is coupled to the transmit port;

a low noise amplifier configured to amplify the input radio frequency signal when the antenna port is coupled to the receive port; and

two external filter leads coupling a band pass filter outside the integrated circuit between the low noise amplifier and the receive port of the transmit-receive switch.

17. The device of claim 14, further comprising:

an impedance matching circuit coupled between the antenna and the front end module, the impedance matching circuit configured to match an input impedance of the front end module with an impedance of the antenna.

18. the device of claim 14, further comprising:

a second front end module, wherein the front end module and the second front end module are configured to process radio frequency signals at two different frequency bands respectively; and

a diplexer coupled between the antenna and the front end module and the second front end module, wherein the antenna transmits and receives the radio frequency signals at the two different frequency bands, and the diplexer is configured to separate the radio frequency signals at the two different frequency bands.

19. The device of claim 14, further comprising:

a second front end module, wherein the second front end module is configured to process radio frequency signals at a second frequency band; and

a second antenna coupled to the second front end module, wherein the second antenna is configured to transmit and receive the radio frequency signals at the second frequency band; and

wherein the front end module is configured to process radio frequency signals at a first frequency band, and the antenna is configured to transmit and receive the radio frequency signals at the first frequency band.

20. The device of claim 14, wherein the wireless networking device is an wireless access point device.

21. The device of claim 14, wherein the wireless networking device is a base station device that conforms to an IEEE 801.11 standard.

22. A method for transmitting and receiving radio frequency signals, the method comprising:

receiving an input radio frequency signal at an antenna;

when a transmit-receive switch within an integrated circuit is switched to a receive side, transmitting the input radio frequency signal to a band pass filter external to the integrated circuit for attenuating signals outside of a pass band of the band pass filter;

amplifying the input radio frequency signal at a low noise amplifier within the integrated circuit;

amplifying an output radio frequency signal at a power amplifier within the integrated circuit;

when the transmit-receive switch within the integrated circuit is switched to a transmit side, transmitting the output radio frequency signal to the antenna via the transmit-receive switch; and

transmitting the output radio frequency signal at the antenna.

23. The method of claim 22, further comprising:

attenuating, by a low pass filter within the integrated circuit, signals of the output radio frequency signal that have frequencies higher than a cutoff frequency of the low pass filter.

24. The method of claim 22, further comprising:

extracting an information-bearing signal from the input radio frequency signal by demodulating the input radio frequency signal.

25. The method of claim 22, further comprising:

generating the output radio frequency by modulating an information signal with a carrier wave.

26. The method of claim 22, wherein a radio frequency power of the output radio frequency signal is more than 100 mW when the output radio frequency signal leaves the integrated circuit.