High performance receiver architecture and methods thereof

Patent metadata

Field	Value
Publication number	US-9735894-B2
Application number	US-201514665818-A
Country	US
Kind code	B2
Filing date	Mar 23, 2015
Priority date	Mar 23, 2015
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A user equipment (UE), receiver and method are generally described herein. The UE may include a mixer, a local oscillator (LO) and an analog-to-digital converter (ADC). The mixer may downconvert a differential radio frequency (RF) signal using LO signals and provide downconverted signals to the ADC. The mixer may provide decoupled lowpass filtering. The lowpass filter capacitors may retain charge when discharging is completed. For each differential signal, the mixer may have an input pullup resistor, first switches receiving the signal and driven by different LO signals, second switches receiving signals from the first switches such that connected pairs of switches may have driven by different LO signals, an ADC input resistor, charging capacitors each connected between first switches driven by the same LO signal, and grounding capacitors each connected to second switches associated with different RF signal outputs and driven by different LO signals.

First claim

What is claimed is:

1. A receiver comprising:
a mixer configured to downconvert a radio frequency (RF) signal; and
a local oscillator (LO) configured to provide LO signals to the mixer,
wherein the mixer comprises:
a plurality of capacitors and a plurality of resistors that form a plurality of poles, and
pairs of switches, different capacitors of the plurality of capacitors are disposed between and couple together different pairs of the switches,
wherein the plurality of capacitors comprise a pair of grounding capacitors connected to ground, each of the grounding capacitors disposed between one pair of the switches and an output resistor,
wherein the plurality of resistors comprise pullup resistors cofigured to receive a differential mixer input signal,
wherein the plurality of poles is configured to provide decoupled lowpass filtering of a number of signals that pass through the mixer,
wherein the plurality of capacitors forms at least one lowpass filter to perform the lowpass filtering, the at least one lowpass filter configured to retain at least some charge when discharging of the at least one lowpass filter is completed during transfer of the downconverted RF signal through the mixer, and
wherein the plurality of poles comprises a first pole that is dependent on the pullup resistors, duty cycles of the LO signals and the charging capacitors and a second pole that is dependent on a combination of the output resistors, the capacitors between the pairs of switches, and the grounding capacitors.

2. A receiver comprising:
a mixer configured to downconvert a radio frequency (RF) signal; and
a local oscillator (LO) configured to provide LO signals to the mixer;
wherein the mixer comprises a plurality of capacitors and a plurality of resistors that form a plurality of poles, the mixer further comprising pairs of switches, different capacitors disposed between and coupling together different pairs of the switches, wherein the plurality of poles are configured to provide decoupled lowpass filtering of a number of signals that pass through the mixer, wherein the plurality of capacitors form at least one lowpass filter to perform the lowpass filtering, the at least one lowpass filter configured to retain at least some charge when discharging of the at least one lowpass filter is completed during transfer of the downconverted RF signal through the mixer, wherein the mixer comprises a differential mixer input and is configured to receive a differential mixer input signal; and
wherein the mixer further comprises for each signal of the differential mixer input signal:
a pullup resistor configured to receive the differential mixer input signal, a first pair of the switches configured to receive the differential mixer input signal and configured to be driven by different LO signals, a second pair of the switches configured to receive signals from the first pair of switches such that connected pairs of switches of the first and second pair of switches are configured to be driven by the different LO signals, and an output resistor configured to receive signals from the second pair of switches and to provide one signal of a differential output signal.

3. The receiver of claim 2 , wherein the mixer further comprises:
a pair of charging capacitors disposed between the first and second pairs of switches, each of the charging capacitors connected between switches of the first pair of switches configured to be driven by the same LO signal such that the charging capacitors are configured to be discharged at different times and retain at least some charge when discharging is completed, and a pair of grounding capacitors disposed between the second pair of switches and the output resistors, each grounding capacitor connected between ground and switches of the second pair of switches associated with different RF signal outputs and configured to be driven by the different LO signals.

4. The receiver of claim 3 , wherein the poles include a first pole that is dependent on the pullup resistors, duty cycles of the LO signals and the charging capacitors and a second pole that is dependent on a combination of the output resistors, the capacitors between the first and second pairs of switches, and the grounding capacitors.

5. The receiver of claim 4 , wherein the duty cycles of the LO signals are configured such that when in operation the charging capacitors do not completely discharge.

6. The receiver of claim 5 , wherein the LO signals each have a 25% duty cycle and are offset by 50% of a cycle of the LO signals.

7. The receiver of claim 2 , wherein the switches of the first and second pair of switches each comprise metal-oxide-semiconductor field effect transistors.

8. The receiver of claim 3 , wherein the charging capacitors are variable capacitors whose values are configured to be adjusted based on a frequency range of the RF signals.

9. The receiver of claim 2 , further comprising a variable low noise amplifier (LNA) configured to receive the RF signal from the antenna and to provide amplified signals to the mixer.

10. The receiver of claim 2 , wherein the lowpass filters are configured to provide at least about 6 dB of attenuation for a Long Term Evolution (LTE) band 20 blocker signal at 36.68 MHz.

11. The receiver of claim 2 , further comprising:
an antenna configured to receive the RF signal and provide the RF signal.

12. A method of providing a higher performance receiver, the method comprising:
downconverting and lowpass filtering a radio frequency (RF) signal with a plurality of charging capacitors by retaining at least sonic charge on the charging capacitors when discharging of the charging capacitors is completed, and wherein the downconverted signal comprising a low frequency (LF) signal;
lowpass filtering the LF signal; and
digitizing the filtered LF signal.

13. The method of claim 12 , wherein lowpass filtering and downconverting the RF signal comprises:
providing a first current of a differential output o a first pullup resistor and an input of each of a pair of first switches;
providing a second current of the differential output to a second pullup resistor and an input of each of a pair of second switches;
driving each pair of first switches with different local oscillator (LO) signals;
driving each pair of second switches with the different LO signals;
charging a first of the charging capacitors, the first charging capacitor connected between outputs of the first and second switches driven using a first of the LO signals; and
charging a second of the charging capacitors, the second charging capacitor connected between outputs of the first and second switches driven a second of the LO signals.

14. The method of claim 13 , wherein lowpass filtering and downconverting the RF signal further comprises:
providing an output of the first switches to an input of a third pair of switches;
providing an output of the second switches to an input of a fourth pair of switches;
driving each pair of third switches with the different LO signals to discharge the first charging capacitor such that the first charging capacitor is configured to retain at least some charge when discharging is completed; and
driving each pair of fourth switches with the different LO signals to discharge the second charging capacitor such that the second charging capacitor is configured to retain at least some charge when discharging is completed.

15. The method of claim 14 , wherein lowpass filtering and downconverting the RF signal further comprises:
coupling an output of a first of the third switches and a first of the fourth

Assignees

• Intel Ip Corp

Inventors

• Alam Mohammed
• Rakers Patrick

Classifications

• H03D7/1466

  Passive mixer arrangements · CPC title

• H03D7/1458 Primary

  Double balanced arrangements, i.e. where both input signals are differential · CPC title

• H04B15/02 Primary

  Reducing interference from electric apparatus by means located at or near the interfering apparatus · CPC title

• H03D2200/0088

  Reduction of intermodulation, nonlinearities, adjacent channel interference; intercept points of harmonics or intermodulation products · CPC title

• H03D7/1441

  using field-effect transistors (H03D7/145 takes precedence) · CPC title