In some examples, a system includes a digital-to-analog converter (DAC) configured to operate at a clock rate; a mixer configured to up-convert an intermediate-frequency (IF) signal from the DAC to a radio-frequency (RF) signal based on a local oscillator (LO) signal; and an RF filter configured to generate a filtered signal by at least removing, from the RF signal, frequency components greater than a difference between a frequency of the LO signal and one-half of the clock rate and less than a sum of a frequency of the LO signal and one-half of the clock rate, wherein an output node of the RF filter is configured to be coupled to an antenna for transmission of the filtered signal.

An RF frontend integrated circuit (IC) device comprises one or more RF transceivers to transmit and receive RF signals within a first frequency band and a second frequency band that is higher than the first frequency band. The RF frontend IC device further comprises a bidirectional LO signal generation circuit coupled to the one or more transceivers to generate a bidirectional LO signal. The bidirectional LO signal is injected between the first frequency band and the second frequency band. The bidirectional LO signal generation circuit is to perform a high-side LO injection for the RF signals within the first frequency band by injecting the bidirectional LO signal having an LO frequency higher than the first frequency band and to perform a low-side LO injection for the RF signals within the second frequency band by injecting the bidirectional LO signal having the LO frequency lower than the second frequency band.

An RF frontend integrated circuit (IC) device comprises one or more RF transceivers to transmit and receive RF signals within a first frequency band and a second frequency band that is higher than the first frequency band. The RF frontend IC device further comprises a bidirectional LO signal generation circuit coupled to the one or more transceivers to generate a bidirectional LO signal. The bidirectional LO signal is injected between the first frequency band and the second frequency band. The bidirectional LO signal generation circuit is to perform a high-side LO injection for the RF signals within the first frequency band by injecting the bidirectional LO signal having an LO frequency higher than the first frequency band and to perform a low-side LO injection for the RF signals within the second frequency band by injecting the bidirectional LO signal having the LO frequency lower than the second frequency band.

An RF receiver includes a low-noise amplifier (LNA) to receive and amplify RF signals, a transformer-based IQ generator circuit, one or more load resisters, one or more mixer circuit, and a downconverter. The transformer-based IQ generator is to generate a differential in-phase local oscillator (LOI) signal and a differential quadrature (LOQ) signal based on a local oscillator (LO) signal received from an LO. The load resisters are coupled to an output of the transformer-based IQ generator. Each of the load resisters is to couple one of the differential LOI and LOQ signals to a predetermined bias voltage. The mixers are coupled to the LNA and the transformer-based IQ generator to receive and mix the RF signals amplified by the LNA with the differential LOI and LOQ signals to generate an in-phase RF (RFI) signal and a quadrature RF (RFQ) signal. The downconverter is to down convert the RFI signal and the RFQ signal into IF signals.

In some examples, a system includes a digital-to-analog converter (DAC) configured to operate at a clock rate; a mixer configured to up-convert an intermediate-frequency (IF) signal from the DAC to a radio-frequency (RF) signal based on a local oscillator (LO) signal; and an RF filter configured to generate a filtered signal by at least removing, from the RF signal, frequency components greater than a difference between a frequency of the LO signal and one-half of the clock rate and less than a sum of a frequency of the LO signal and one-half of the clock rate, wherein an output node of the RF filter is configured to be coupled to an antenna for transmission of the filtered signal.

An RF receiver includes a low-noise amplifier (LNA) to receive and amplify RF signals, a transformer-based IQ generator circuit, one or more load resisters, one or more mixer circuit, and a downconverter. The transformer-based IQ generator is to generate a differential in-phase local oscillator (LOI) signal and a differential quadrature (LOQ) signal based on a local oscillator (LO) signal received from an LO. The load resisters are coupled to an output of the transformer-based IQ generator. Each of the load resisters is to couple one of the differential LOI and LOQ signals to a predetermined bias voltage. The mixers are coupled to the LNA and the transformer-based IQ generator to receive and mix the RF signals amplified by the LNA with the differential LOI and LOQ signals to generate an in-phase RF (RFI) signal and a quadrature RF (RFQ) signal. The downconverter is to down convert the RFI signal and the RFQ signal into IF signals.

The present invention is related to a method and apparatus for processing multiple wireless communication services in a receiver. A receiver receives more than one wireless communication service simultaneously via a wireless interface. Each service is transmitted via a different carrier frequency band. The multiple received carrier signals are down-converted to an intermediate frequency (IF) band using a mixer and a local oscillator (LO). The LO frequencies are set such that the down-converted IF bands of the multiple services are fallen into a single IF band.