Patent attributes
A radio frequency (RF) device includes a plurality of mixers, each of the plurality of mixers having a first input terminal, a second input terminal, and an output terminal; and a self-test circuit. The self-test circuit includes a buffer having an input terminal and an output terminal, the buffer configured to buffer a reference signal from a local oscillator (LO) to produce a first RF signal at a first frequency; and a plurality of delay elements having different respective transmission delays, the delay elements each having a first end coupled to the output terminal of the buffer and a second end configured to provide a respective delayed signal based on the first RF signal, where the self-test circuit is configured to, in a test mode, couple the second ends of the delay elements to respective first input terminals of the plurality of mixers to provide each mixer with the respective delayed signal, and where the second input terminals of the mixer are configured to receive a second RF signal having the first frequency.