Method and apparatus of an input resistance of a passive mixer to broaden the input matching bandwidth of a common source-gate LNA

• US 9,287,836 B2
• Filed: 12/16/2013
• Issued: 03/15/2016
• Est. Priority Date: 12/06/2011
• Status: Active Grant

• Current Assignee: Tensorcom Inc
• Original Assignee: Tensorcom Inc
• Inventors: Soe, Zaw
• Primary Examiner(s): Jackson, Blane J
• Application Number:
  US14/108,312
• Publication Number:
  US 20140097894A1
• Time in Patent Office: 820 Days
• Field of Search: 455/323, 455/313, 455/333, 455/334, 455/341, 330/305
• US Class Current: 1/1
• CPC Class Codes: H03D 7/125 with field effect transistors
• CPC Class Codes: H03D 7/1441 using field-effect transistors H03D7/145 takes precedence
• CPC Class Codes: H03D 7/1466 Passive mixer arrangements
• CPC Class Codes: H03D 7/165 at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature combined with amplitude demodulation H03D1/2245, combined with angle demodulation H03D3/007; N-path filters H03H19/002
• CPC Class Codes: H03F 1/223 with MOSFET's
• CPC Class Codes: H03F 1/42 Modifications of amplifiers to extend the bandwidth
• CPC Class Codes: H03F 2200/108 A coil being added in the drain circuit of a FET amplifier stage, e.g. for noise reducing purposes
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/492 A coil being added in the source circuit of a transistor amplifier stage as degenerating element
• CPC Class Codes: H03F 2200/72 the amplifier stage being a common gate configuration MOSFET
• CPC Class Codes: H03F 2200/75 the amplifier stage being a common source configuration MOSFET
• CPC Class Codes: H03F 3/193 with field-effect devices H03F3/195 takes precedence
• CPC Class Codes: H03F 3/387 with semiconductor devices only
• CPC Class Codes: H03F 3/45071 with semiconductor devices only
• CPC Class Codes: H03F 3/45179 using MOSFET transistors as the active amplifying circuit H03F3/45278 takes precedence
• CPC Class Codes: H04L 27/38 Demodulator circuits; Receiver circuits

Abstract

A cascode common source and common gate LNAs operating at 60 GHz are introduced and described. The cascode common source LNA is simulated to arrive at an optimum ratio of upper device width to the lower device width. The voltage output of the cascode common source LNA is translated into a current to feed and apply energy to the mixer stage. These input current signals apply the energy associated with the current directly into the switched capacitors in the mixer to minimize the overall power dissipation of the system. The LNA is capacitively coupled to the mixer switches in the I and Q mixers and are enabled and disabled by the clocks generated by the quadrature oscillator. These signals are then amplified by a differential amplifier to generate the sum and difference frequency spectra.

Claims

1. A receiver comprising:

a Low Noise Amplifier (LNA) coupled to a resonant circuit providing an output signal spectrum;

a capacitor couples the output signal spectrum to a first switched capacitor circuit;

an oscillator clock coupled to the first switched capacitor circuit;

the first switched capacitor circuit presents a first impedance to the resonant circuit; and

the first switched capacitor circuit is configured to mix the oscillator clock and the output signal spectrum into a first mixed signal.

2. The receiver of claim 1, wherein

the first impedance of the first switched capacitor circuit adjusts a Q of the resonant circuit.

3. The receiver of claim 1, further comprising:

the output signal spectrum coupled to a second switched capacitor circuit;

an inverse oscillator clock coupled to the second switched capacitor circuit;

the second switched capacitor circuit presents a second impedance to the resonant circuit; and

the second switched capacitor circuit is configured to mix the inverse oscillator clock and the output signal spectrum into a second mixed signal.

4. The receiver of claim 3, wherein

the first mixed signal and the second mixed signal is a differential intermediate frequency signal.

5. The receiver of claim 4, further comprising:

a differential amplifier coupled to the differential intermediate frequency signal.

6. The receiver of claim 5, wherein

the first switched capacitor circuit and the second switched capacitor circuit comprise a first mixer.

7. The receiver of claim 6, wherein

energy from the resonant circuit is used to power the first mixer.