Honeywell International Inc.
Fixed low intermediate frequency approach to distance measurement transmitter

Abstract:

A device and techniques for generating and filtering a signal for transmission, such as the signal used to interrogate distance measuring equipment (DME), which may be tuned to a channel or frequency selected from a wide bandwidth. A system according to the techniques of this disclosure may generate a narrow band intermediate frequency (IF) signal with desired pulse characteristics, mix the IF signal with a local oscillator (LO) to upconvert to the desired radio frequency (RF) signal, then filter the upconverted RF signal through one of several narrow band filters in a filter bank to remove any undesired signal images. The system may select the filter from the filter bank depending on the transmitted RF frequency. In this manner the system of this disclosure may generate signals to span a wide RF bandwidth by using a narrow bandwidth IF signal generator.