Complex-pole load offering concurrent image rejection and channel selection

Patent metadata

Field	Value
Publication number	US-9479140-B2
Application number	US-201414255094-A
Country	US
Kind code	B2
Filing date	Apr 17, 2014
Priority date	Apr 16, 2014
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A complex-pole load is configured as a parallel circuit, having 4 transistors arranged in pairs. Each pair of transistors has a transistor gated by a control voltage sources, and connected in parallel with a transistor diode connected for gating by the respective input. The control voltage sources result in the circuit synthesizing a first order complex pole at a positive IF (+IF) or a negative IF (−IF) for channel selection and image rejection, offering image rejection and channel selection concurrently.

First claim

What is claimed is:

1. A complex pole load comprising:
a parallel circuit comprising 8 transistors arranged in four pairs, with each pair receiving filtered output currents from a biquad filter circuit as an input to conduct I and Q current, respectively, in the pairs,
each pair of transistors comprising a transistor in one pair gated by control voltage sources, connected in parallel with a transistor diode connected for gating by the respective input of a transistor in the other pair, and
the control voltage sources comprising complex voltage components, with an I channel driven by Q channel IF signals, and a Q channel driven by I channel IF signals, resulting in the circuit synthesizing a first order complex pole load at a positive IF (+IF) or a negative IF (IF) for channel selection and image rejection, offering image rejection and channel selection concurrently.

2. The IF-noise-shaping transistorized current-mode lowpass filter of claim 1 , further comprising:
a second set of circuit elements, thereby separately applying the pole loads to I and Q complex signals.

Assignees

• Univ Macau

Inventors

• Lin Zhicheng
• Mak Pui-In
• Martins Rui Paulo Da Silva

Classifications

• H04B2001/1072

  by tuning the receiver frequency · CPC title

• H04L27/3809

  Amplitude regulation arrangements · CPC title

• H04B1/123

  using adaptive balancing or compensation means (adaptive filter circuits and algorithms H03H) · CPC title

• H03F3/193

  with field-effect devices (H03F3/195 takes precedence) · CPC title

• H04W4/80

  Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication · CPC title