A multi-mixer system includes an amplifier module and a plurality of channels. The amplifier module is arranged for receiving signals from an antenna or antenna arrays to generate a plurality of radio frequency (RF) input signals. The plurality of channels are coupled to the amplifier module, wherein the plurality of channels receive the RF input signals, respectively, and each of the channels includes a mixer for mixing one of the RF input signals with a local oscillating signal to generate a mixed signal. In addition, at least one of the channels includes an interference reduction circuit positioned between the amplifier module and the mixer.

A multi-mixer system includes an amplifier module and a plurality of channels. The amplifier module is arranged for receiving signals from an antenna or antenna arrays to generate a plurality of radio frequency (RF) input signals. The plurality of channels are coupled to the amplifier module, wherein the plurality of channels receive the RF input signals, respectively, and each of the channels includes a mixer for mixing one of the RF input signals with a local oscillating signal to generate a mixed signal. In addition, at least one of the channels includes an interference reduction circuit positioned between the amplifier module and the mixer.

An apparatus for a multi-antenna transceiver is disclosed. The multi-antenna transceiver has a plurality of antenna elements connected to respective transceiver chains. Each transceiver chain includes a frequency converter operated using a respective local oscillator signal provided by a respective phase-locked loop. The apparatus includes a controller configured to cause control of the respective phase-locked loop of one or more transceiver chain to generate the respective local oscillator signal with a respective phase offset for mitigation of local oscillator leakage through the frequency converter. In some embodiments, the controller is further configured to cause, for each transceiver chain with a non-zero respective phase offset, a corresponding phase adjustment of a signal for frequency conversion. Corresponding multi-antenna transceivers, wireless communication devices and methods are also disclosed.

An apparatus for a multi-antenna transceiver is disclosed. The multi-antenna transceiver has a plurality of antenna elements connected to respective transceiver chains. Each transceiver chain includes a frequency converter operated using a respective local oscillator signal provided by a respective phase-locked loop. The apparatus includes a controller configured to cause control of the respective phase-locked loop of one or more transceiver chain to generate the respective local oscillator signal with a respective phase offset for mitigation of local oscillator leakage through the frequency converter. In some embodiments, the controller is further configured to cause, for each transceiver chain with a non-zero respective phase offset, a corresponding phase adjustment of a signal for frequency conversion. Corresponding multi-antenna transceivers, wireless communication devices and methods are also disclosed.

Disclosed is a system for mitigating unwanted emissions in an integrated antenna in which the uplink and downlink RF processing chains are located in close proximity and shielding is impractical. The system involves orienting the uplink and downlink processing chains and physically locating them relative to each other so that applying selective phase biases to their local oscillators results in local oscillator leakage from adjacent RF processing chains to have an out of phase relationship relative to each other. This mitigates unwanted emission from local oscillator signals leakage from the RF processing chains' mixers by angularly dispersing the unwanted emissions and attenuating the unwanted emissions through destructive interference.

Disclosed is a system for mitigating unwanted emissions in an integrated antenna in which the uplink and downlink RF processing chains are located in close proximity and shielding is impractical. The system involves orienting the uplink and downlink processing chains and physically locating them relative to each other so that applying selective phase biases to their local oscillators results in local oscillator leakage from adjacent RF processing chains to have an out of phase relationship relative to each other. This mitigates unwanted emission from local oscillator signals leakage from the RF processing chains' mixers by angularly dispersing the unwanted emissions and attenuating the unwanted emissions through destructive interference.

A transceiver includes local oscillator (LO) signal circuitry configured to output an LO signal having an LO frequency and mixer circuitry configured to input the LO signal and an information signal that encodes communication data and output a shifted signal that corresponds to the information signal shifted to a desired frequency. The LO signal circuitry includes selection circuitry and generation circuitry. The selection circuitry is configured to select a pulse pattern and a gap duration based at least on a target harmonic of the LO frequency to be suppressed. The pulse pattern includes at least two pulses spaced apart by a gap having the gap duration. The generation circuitry is configured to generate an LO signal characterized by the selected pulse pattern and gap duration.

A transceiver includes local oscillator (LO) signal circuitry configured to output an LO signal having an LO frequency and mixer circuitry configured to input the LO signal and an information signal that encodes communication data and output a shifted signal that corresponds to the information signal shifted to a desired frequency. The LO signal circuitry includes selection circuitry and generation circuitry. The selection circuitry is configured to select a pulse pattern and a gap duration based at least on a target harmonic of the LO frequency to be suppressed. The pulse pattern includes at least two pulses spaced apart by a gap having the gap duration. The generation circuitry is configured to generate an LO signal characterized by the selected pulse pattern and gap duration.

In one form, a spread spectrum clock generator includes an oscillator and a digital modulator. The oscillator has a control input for setting an output frequency, and an output for providing a clock output signal. The digital modulator is responsive to the clock output signal to provide a control code to the control input of the oscillator as a periodic signal with a plurality of discrete steps, wherein the digital modulator provides said control code at each of said plurality of discrete steps for substantially a predetermined time.

Apparatus and methods for disrupting or preventing periodicity in DTC circuits are provided. In an example, a communication circuit can include a digital-to-time converter (DTC) and a processing path coupled to the DTC. The DTC can be configured to receive reference information, modulation information and first dither information, and to provide a modulated signal using the reference information, the modulation information and the first dither information. The processing path can be configured to receive second dither information and to cancel the first dither information using the second dither information, wherein the DTC is configured to disrupt processing periodicity of the communication circuit using the first dither information.