Patent Number: 6,298,223

Title: Detector circuit and method of detecting antenna mismatch

Abstract: A detector circuit (1) includes a coupler (2) having a primary port (10) and a reflector port (11). The primary port (10) has an input node for receiving radio frequency signals from an amplifier (7) and an output node coupled to an antenna port (ANT). There is a rectification circuit (3) having an input coupled to the reflector port (2) and a low pass filter (4) is coupled to an output of the rectification circuit (3). The detector circuit also includes a comparator (5) having a reference input (Vref) and a signal input (Vin). The reference input (Vref) is set to a voltage threshold level and the signal input is coupled to an output of the low pass filter (4). In use signals at an output of the comparator (5) are indicative of a missing or mismatched antenna coupled to the antenna port (ANT).

Inventors: Seow; Boon Eu (Bayan Baru, MY)

Assignee: Motorola, Inc.

International Classification: H04B 1/04 (20060101); H01Q 011/12 ()

Expiration Date: 10/02/2018