DW9255

The DW9255 is a Surface Acoustic Wave (SAW) bandpass filter for use with the GP2000 Global Positioning System (GPS) receiver chip-set, available from Mitel Semiconductor. It is pre-tuned to the exact 2nd IF filter requirements of the GP2010 & GP2015 RF front-end devices, with a centrefrequency of 35.42MHz. The response is tuned for a flat passband, steep stopband and uniform passband group-delay with 3 external inductors. The device is realised on a Lithium Tantalate substrate and housed in a small leadless ceramic Surface Mount package.

The DW9255 gives significant improvement in correlated GPS Signal-to-Noise Ratio (SNR) performance compared to conventional LC bandpass filter schemes. This aids satellite signal acquisition and tracking capability from the GP2000 GPS chip-set. This device effectively filters out-of-band (unwanted) noise in the GPS signal. The Automatic Gain Control (AGC) within the GP2010 and GP2015 RF Front-end devices will then operate only on in-band noise for optimum gain and superior correlated GPS signal strength.