Abstract: Included are embodiments for enhanced carrier suppression. One embodiment of a circuit includes a mixer that receives a cover sequence, the cover sequence including transition data from a first signal and a second signal. The mixer may be configured to generate a modulated cover sequence by modulating a radio frequency (RF) carrier with the cover sequence. Some embodiments also include a modulator that is communicatively coupled to the mixer. The modulator may be configured to receive and modulate an altered version of the first signal and an altered version of the second signal. The modulator may additionally receive the modulated cover sequence as an RF carrier input and generate an RF output by modulating the modulated cover sequence with the altered version of the first signal and the altered version of the second signal.

Abstract: Included are embodiments for enhanced carrier suppression. One embodiment of a circuit includes a mixer that receives a cover sequence, the cover sequence including transition data from a first signal and a second signal. The mixer may be configured to generate a modulated cover sequence by modulating a radio frequency (RF) carrier with the cover sequence. Some embodiments also include a modulator that is communicatively coupled to the mixer. The modulator may be configured to receive and modulate an altered version of the first signal and an altered version of the second signal. The modulator may additionally receive the modulated cover sequence as an RF carrier input and generate an RF output by modulating the modulated cover sequence with the altered version of the first signal and the altered version of the second signal.

Abstract: An FM receiver is self tested by connecting a positive feedback network in circuit with a wideband, front end r.f. amplifier of the receiver, so that the amplifier is converted into an oscillator. R.f. and i.f. characteristics of the receiver are determined by comparing the amplitude of an i.f. signal with a predetermined reference value while the amplifier is converted to an oscillator. Noise characteristics of the receiver are determined by comparing the amplitude of an audio frequency signal of the receiver with a predetermined value while the amplifier is converted to an oscillator and the amplifier derives an unmodulated r.f. output. Baseband characteristics of the receiver are determined by varying a reactance in the positive feedback path to impose FM on r.f. oscillations derived by the amplifier and by comparing the amplitude of the output of the audio frequency amplifier with a predetermined value.