Filter i.e. surface acoustic wave type filter, drift compensation permitting system for e.g. transmitter-channel, has device determining frequency shift to be applied to filter and with oscillators synchronized on frequency reference

摘要

The system has a digital block (1) with a temperature sensor (2) determining a value of parameters that produce drift of a filter (7) e.g. surface acoustic wave (SAW) type filter. A field-programmable gate array (FPGA) programmable device (3) comprises local oscillators (5, 6) and filter drift laws based on parameters, and determines frequency shift to be applied to the filter. The oscillators are synthesized and synchronized on a same frequency reference. Mixers (8, 9) permit to mix a frequency obtained from the oscillators with another frequency. The filter is placed between the mixers. An independent claim is also included for a method permitting to compensate a filter drift that is variable under the effect of a parameter in a double frequency change device.