Front-End System for Radio Devices

• US 20130214863A1
• Filed: 02/15/2013
• Published: 08/22/2013
• Est. Priority Date: 02/17/2012
• Status: Active Grant

• Current Assignee: IMEC International
• Original Assignee: IMEC International
• Inventors: Vidojkovic, Vojkan, Vaesen, Kristof, Wambacq, Piet
• Granted Patent: US 8,971,831 B2
• Time in Patent Office: Days
• US Class Current: 330/260
• CPC Class Codes: H03F 2200/141 the feedback circuit of the amplifier stage comprising a resistor and a capacitor in series, at least one of them being an active one
• CPC Class Codes: H03F 2200/144 the feedback circuit of the amplifier stage comprising a passive resistor and passive capacitor
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/534 Transformer coupled at the input of an amplifier
• CPC Class Codes: H03F 2200/537 A transformer being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 2200/541 Transformer coupled at the output of an amplifier
• CPC Class Codes: H03F 3/45071 with semiconductor devices only
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 1/30 for homodyne or synchrodyne receivers demodulator circuits H03D1/22

Abstract

The present disclosure relates to a front-end system for a radio device, the front-end system comprising a low-noise amplifier (LNA), arranged for receiving a radio frequency input signal (RF_IN) and arranged for outputting an amplified radio frequency signal (RF_OUT), wherein the low-noise amplifier comprises a first differential amplifier, and a mixer (MIX), arranged for down-converting the amplified radio signal (RF_OUT) provided by the low-noise amplifier (LNA) to a baseband signal (BB), by multiplying the amplified radio signal (RF_OUT) with a local oscillator (LO) frequency tone, said low-noise amplifier (LNA) and said mixer (MIX) being inductively coupled.

Claims

1. A front-end system for a radio device comprising:

a low-noise amplifier arranged for receiving an input signal and for outputting an amplified signal; and

a mixer arranged for down-converting the amplified signal provided by the low-noise amplifier to a baseband signal by multiplying the amplified signal with a local oscillator frequency tone, wherein the low-noise amplifier and the mixer are transformer-coupled.

2. The front-end system of claim 1, wherein the low-noise amplifier includes a neutralization circuit comprising a cross-coupled capacitor.

3. The front-end system of claim 1, wherein the low-noise amplifier includes a resistive shunt feedback circuit.

4. The front-end system of claim 1, wherein the-low-noise amplifier comprises a first amplification stage and a second amplification stage.

5. The front-end system of claim 4, wherein the first amplification stage includes a resistive shunt feedback circuit, and wherein the resistive shunt feedback circuit further includes a capacitor connected in series with a resistor that provide DC decoupling for the low-noise amplifier.

6. The front-end system of claim 4, wherein the second amplification stage is inductively coupled to the first amplification stage.

7. The front-end system of claim 1, wherein the low-noise amplifier is inductively coupled to an antenna.

8. The front-end system of claim 1, further comprising, at an input of the low-noise amplifier, an input transformer with a turn ratio of about 1:

3 and coupling factor of about 0.5.

9. The front-end system of claim 1, wherein the mixer is a passive voltage switching mixer.

10. The front-end system of claim 1, wherein the mixer is implemented differentially.

14. The front-end system of claim 1, wherein the-low-noise amplifier comprises a first amplification stage and a second amplification stage.

15. The radio device of claim 14, wherein the first amplification stage includes a resistive shunt feedback circuit, and wherein the resistive shunt feedback circuit further includes a capacitor connected in series with a resistor that provide DC decoupling for the low-noise amplifier.

16. The radio device of claim 14, wherein the second amplification stage is inductively coupled to the first amplification stage.

11. A radio device comprising a front-end system, wherein the front end system includes:

a low-noise amplifier arranged for receiving an input signal and for outputting an amplified signal; and

a mixer arranged for down-converting the amplified signal provided by the low-noise amplifier to a baseband signal by multiplying the amplified signal with a local oscillator frequency tone, wherein the low-noise amplifier and the mixer are transformer-coupled.

12. The radio device of claim 11, wherein the low-noise amplifier includes a neutralization circuit comprising a cross-coupled capacitor.

13. The radio device of claim 11, wherein the low-noise amplifier includes a resistive shunt feedback circuit.

17. The radio device of claim 11, wherein the low-noise amplifier is inductively coupled to an antenna.

18. The radio device of claim 11, further comprising, at an input of the low-noise amplifier, an input transformer with a turn ratio of about 1:

3 and coupling factor of about 0.5.

19. The radio device of claim 11, wherein the mixer is a passive voltage switching mixer.

20. The radio device of claim 11, wherein the mixer is implemented differentially.