Down-Converter Application Circuit for PHP Systems

The PHP cordless telephone standard operates in the 1900 MHz band. This application note describes the use of the CMY 91 as a first down conversion mixer of a PHP receiver. The CMY 91 is packaged in a SOT-23 sized package, operates from a single positive 3 V supply and has a low power consumption.

APPLICATION Circuit
The CMY 91 consists of a mixer (GaAs-FET), followed by a IF amplifier in series with the signal path. The resulting IF signal is then amplified by a selfbiased amplifier to give an overall conversion gain of typically 7 dB.