BACKGROUND

Technical Field

Embodiments of the invention relate to electronic systems, and in particular, to radio frequency (RF) electronics.

Description of Related Technology

A communication system can include a transceiver, a front end, and one or more antennas for wirelessly transmitting and/or receiving signals. The front end can include low noise amplifier(s) for amplifying relatively weak signals received via the antenna(s), and power amplifier(s) for boosting signals for transmission via the antenna(s).

Examples of communication systems include, but are not limited to, mobile phones, tablets, base stations, network access points, customer-premises equipment (CPE), laptops, and wearable electronics.

SUMMARY

In certain embodiments, the present disclosure relates to a radio frequency system. The radio frequency system includes two or more frequency downconverters configured to output two or more analog baseband signals in response to receiving a plurality of radio frequency signals from an antenna array. The radio frequency system further includes a controllable amplification and combining circuit configured to generate two or more amplified analog baseband signals based on amplifying each of the two or more analog baseband signals with a separately controllable gain, and to combine the two or more amplified analog baseband signals to generate a combined analog baseband signal. The radio frequency system further includes a data conversion and signal processing circuit configured to receive the combined signal.

In some embodiments, the controllable amplification and combining circuit is configured to generate the combined analog baseband signal in a first mode, and to output the two or more amplified analog baseband signals in a second mode. According to a number of embodiments, the radio frequency system operates with beamforming in the first mode and with diversity communications in the second mode.

In several embodiments, the controllable amplification and combining circuit includes two or more controllable gain input amplifiers configured to amplify the two or more analog baseband signals to generate the two or more amplified analog baseband signals. In accordance with various embodiments, the controllable amplification and combining circuit further includes two or more DC offset compensation circuits each configured to provide a separately controllable DC offset correction to a corresponding one of the two or more controllable gain input amplifiers.

In some embodiments, the data conversion and signal processing circuit includes two or more analog-to-digital converters each configured to receive a corresponding one of the two or more amplified analog baseband signals.

In various embodiments, the radio frequency system further includes two or more local oscillators configured to control downconversion of the two or more frequency downconverters. According to a number of embodiments, the two or more local oscillators each include a phase-locked-loop configured to receive a common timing reference signal.

In certain embodiments, the present disclosure relates to a method of radio frequency communication. The method includes receiving a radio wave using a plurality of antenna elements of an antenna array, generating two or more analog baseband signals using a plurality of radio frequency circuit channels each coupled to a corresponding one of the plurality of antenna elements, amplifying each of the two or more analog baseband signals with a separately controllable gain using a controllable amplification and combining circuit, and combining the two or more amplified analog baseband signals to generate a combined analog baseband signal using the controllable amplification and combining circuit.

In various embodiments, the method further includes generating the combined analog baseband signal in a first mode of the controllable amplification and combining circuit, and outputting the two or more amplified analog baseband signals in a second mode of the controllable amplification and combining circuit. According to a number of embodiments, the method further includes forming a receive beam in the first mode and operating with diversity communications in the second mode.

In a number of embodiments, the method further includes compensating for a DC offset of each of the two or more amplified analog baseband signals.

In some embodiments, the method further includes converting the combined analog baseband signal to a digital signal.

In various embodiments, the method further includes performing phase shifting in each of the radio frequency circuit channels at an intermediate frequency that is less than a frequency of the radio wave.

In several embodiments, the method further includes generating a plurality of clock signals using a plurality of local oscillators operating with a common timing reference signal, and providing each of the plurality of clock signals to a corresponding one of the plurality of radio frequency circuit channels.

In some embodiments, the method further includes generating a first intermediate frequency signal using a first radio frequency circuit channel of the plurality of radio frequency circuit channels, generating a second intermediate frequency signal using a second radio frequency circuit channel of the plurality of radio frequency circuit channels, and combining the first intermediate frequency signal and the second intermediate frequency signal.

In certain embodiments, the present disclosure relates to a communication system. The communication system includes an antenna array including a plurality of antenna elements, a plurality of radio frequency circuit channels each coupled to a corresponding one of the plurality of antenna elements, and a controllable amplification and combining circuit. The plurality of radio frequency circuit channels are operable to generate two or more analog baseband signals in response to the antenna array receiving a radio wave. Additionally, the controllable amplification and combining circuit is configured to generate two or more amplified analog baseband signals based on amplifying each of the two or more analog baseband signals with a separately controllable gain, and to combine the two or more amplified analog baseband signals to generate a combined analog baseband signal.

In various embodiments, the controllable amplification and combining circuit is configured to generate the combined analog baseband signal in a first mode, and to output the two or more amplified analog baseband signals in a second mode. According to a number of embodiments, the communication system operates with beamforming in the first mode and with diversity communications in the second mode.

In some embodiments, the controllable amplification and combining circuit includes two or more controllable gain input amplifiers configured to amplify the two or more analog baseband signals to generate the two or more amplified analog baseband signals. According to a number of embodiments, the controllable amplification and combining circuit further includes two or more DC offset compensation circuits each configured to provide a separately controllable DC offset correction to a corresponding one of the two or more controllable gain input amplifiers.

In several embodiments, the communication system further includes a data conversion and signal processing circuit including two or more analog-to-digital converters each configured to receive a corresponding one of the two or more amplified analog baseband signals.

In a number of embodiments, the plurality of radio frequency circuit channels each include a controllable phase shifter configured to provide phase shifting at an intermediate frequency that is less than a frequency of the radio wave.

In some embodiments, the communication system further includes a plurality of local oscillators each configured to provide at least one clock signal to a corresponding one of the plurality of radio frequency circuit channels. According to various embodiments, the plurality of local oscillators each include a phase-locked-loop configured to receive a common timing reference signal.

In several embodiments, the plurality of radio frequency circuit channels includes a first radio frequency circuit channel including a first mixer configured to generate a first intermediate frequency signal, and a second radio frequency circuit channel including a second mixer configured to generate a second intermediate frequency signal. According to a number of embodiments, the communication system further includes a combiner configured to generate a first analog baseband signal of the two or more analog baseband signals based on combining the first intermediate frequency signal and the second intermediate frequency signal.

In certain embodiments, the present disclosure relates to a semiconductor die. The semiconductor die includes a plurality of controllable gain input amplifiers configured to amplify a plurality of analog baseband signals to generate a plurality of amplified analog baseband signals, each of the plurality of controllable gain input amplifiers configured to amplify a corresponding one of the plurality of analog baseband signals with a separately controllable amount of gain. The semiconductor die further includes a plurality of selection circuits each configured to receive a respective one of the plurality of amplified baseband signals, the plurality of selection signals configured to combine the plurality of amplified analog baseband signals to generate a combined analog baseband signal in a first mode, and to output the plurality of amplified analog baseband signals in a second mode.

In a number of embodiments, the semiconductor die further includes a plurality of DC offset compensation circuits each configured to provide a separately controllable DC offset correction to a corresponding one of the plurality of controllable gain input amplifiers.

In several embodiments, the plurality of selection circuits are implemented as a plurality of cascode transistors.

In some embodiments, the plurality of controllable gain input amplifiers are implemented as a plurality of gain stages, the separately controllable amount of gain based on a number of the plurality of gain stages that are selected. According to a number of embodiments, the plurality of gain stages are weighted.

In various embodiments, the semiconductor die further includes a plurality of output buffers each configured to buffer a corresponding one of the plurality of amplified analog baseband signals.

In several embodiments, the semiconductor die further includes a plurality of analog-to-digital converters each configured to provide analog-to-digital conversion to a corresponding one of the plurality of amplified analog baseband signals in the second mode. According to a number of embodiments, a first analog-to-digital converter of the plurality of analog-to-digital converters is configured to provide analog-to-digital conversion to the combined analog baseband signal in the first mode. In accordance with various embodiments, one or more of the plurality of analog-to-digital converters are disabled in the first mode to reduce power consumption.

In certain embodiments, the present disclosure relates to a method of processing signals in a communication system. The method includes amplifying a plurality of analog baseband signals to generate a plurality of amplified analog baseband signals using a plurality of controllable gain input amplifiers, including amplifying each of the plurality of analog baseband signals using a corresponding one of the plurality of controllable gain input amplifiers. The method further includes separately controlling a gain of each of the plurality of controllable gain input amplifiers. The method further includes processing the plurality of amplified analog baseband signals using a signal selector that includes a plurality of selection circuits each receiving a corresponding one of the plurality of amplified analog baseband signals, including outputting a combined analog baseband signal in a first mode of the signal selector and outputting the plurality of amplified analog baseband signals in a second mode of the signal selector.

In some embodiments, the method further includes providing DC offset correction to the plurality of controllable gain input amplifiers using a plurality of DC offset compensation circuits, including correcting a DC offset of each of the plurality of controllable gain input amplifiers using a corresponding one of the plurality of DC offset compensation circuits.

In various embodiments, separately controlling a gain of each of the plurality of controllable gain input amplifiers includes controlling a number of active gain stages of each of the plurality of controllable gain input amplifiers.

In a number of embodiments, the method further includes buffering the plurality of amplified analog baseband signals.

In some embodiments, the method further includes providing analog-to-digital conversion of the plurality of amplified analog baseband signals using a plurality of analog-to-digital converters in the second mode. In accordance with several embodiments, the method further includes providing analog-to-digital conversion of the combined analog baseband signal using a first analog-to-digital converter of the plurality of analog-to-digital converters in the first mode. According to a number of embodiments, the method further includes deactivating one or more of the plurality of analog-to-digital converters in the first mode.

In certain embodiments, the present disclosure relates to a communication system. The communication system includes a plurality of radio frequency circuit channels configured to output a plurality of analog baseband signals, and a controllable amplification and combining circuit including a plurality of controllable gain input amplifiers configured to amplify the plurality of analog baseband signals to generate a plurality of amplified analog baseband signals, each of the plurality of controllable gain input amplifiers configured to amplify a corresponding one of the plurality of analog baseband signals with a separately controllable amount of gain. The controllable amplification and combining circuit further includes a plurality of selection circuits each configured to receive a respective one of the plurality of amplified baseband signals, the plurality of selection signals configured to combine the plurality of amplified analog baseband signals to generate a combined analog baseband signal in a first mode, and to output the plurality of amplified analog baseband signals in a second mode.

In various embodiments, the controllable amplification and combining circuit further includes a plurality of DC offset compensation circuits each configured to provide a separately controllable DC offset correction to a corresponding one of the plurality of controllable gain input amplifiers.

In a number of embodiments, the plurality of selection circuits are implemented as a plurality of cascode transistors.

In several embodiments, the plurality of controllable gain input amplifiers are implemented as a plurality of gain stages, and the separately controllable amount of gain based on a number of the plurality of gain stages that are selected. In accordance with some embodiments, the plurality of gain stages are weighted.

In various embodiments, the controllable amplification and combining circuit further includes a plurality of output buffers each configured to buffer a corresponding one of the plurality of amplified analog baseband signals.

In some embodiments, the communication system further includes a data conversion and signal processing circuit configured to receive the combined analog baseband signal in the first mode, and the plurality of amplified analog baseband signals in the second mode.

In several embodiments, the data conversion and signal processing circuit includes a plurality of analog-to-digital converters each configured to provide analog-to-digital conversion to a corresponding one of the plurality of amplified analog baseband signals in the second mode. In accordance with a number of embodiments, a first analog-to-digital converter of the plurality of analog-to-digital converters is configured to provide analog-to-digital conversion to the combined analog baseband signal in the first mode. According to various embodiments, the one or more of the plurality of analog-to-digital converters are disabled in the first mode to reduce power consumption.

In some embodiments, the communication system further includes an antenna array including a plurality of antenna elements coupled to the plurality of radio frequency circuit channels.

