Abstract: An RF transceiver apparatus has transmitter circuitry receiving transmission signals at a transmitter baseband frequency and converting the signals to a transmission frequency, and receiver circuitry receiving signals at a reception frequency and converting to a receiver baseband frequency. A first digital local oscillator and a first mixer convert between the transmitter baseband frequency and a transmitter intermediate frequency. A second digital local oscillator and a second mixer convert between a receiver intermediate frequency and the receiver baseband frequency. A third mixer frequency receives a local oscillator signal for frequency conversion between the transmitter intermediate frequency and the transmission frequency. A fourth mixer frequency receives a local oscillator signal for frequency conversion between the reception frequency and the receiver intermediate frequency.

Abstract: An RF transceiver apparatus has transmitter circuitry receiving transmission signals at a transmitter baseband frequency and converting the signals to a transmission frequency, and receiver circuitry receiving signals at a reception frequency and converting to a receiver baseband frequency. A first digital local oscillator and a first mixer convert between the transmitter baseband frequency and a transmitter intermediate frequency. A second digital local oscillator and a second mixer convert between a receiver intermediate frequency and the receiver baseband frequency. A third mixer frequency receives a local oscillator signal for frequency conversion between the transmitter intermediate frequency and the transmission frequency. A fourth mixer frequency receives a local oscillator signal for frequency conversion between the reception frequency and the receiver intermediate frequency.

Abstract: A transceiver circuit includes: a transmit path with at least one of each of a digital to analog converter converting a digital input signal to an analog signal, a filter, a first frequency synthesizer, a mixer to produce an RF output, and an amplifier amplifying the RF output for transmission; and a receive path with at least one of each of a second amplifier amplifying a received RF input, a second frequency synthesizer, a second mixer to produce a baseband signal, a second filter, and an analog to digital converter converting the baseband signal to a digital output signal; at least one switch selectively connecting different points of the circuit thereby to bypass at least one component of the circuit; and a control input connected to the switch to receive control signals for controlling operation of the switch.

Abstract: A transceiver circuit comprising a transmit path and a receive path, the transmit path comprising at least one digital to analogue converter for converting a digital input signal to an analogue signal, at least one filter for filtering the analogue signal, at least one first frequency synthesizer for producing a first synthesized RF signal, at least one mixer for mixing the analogue signal with the RF signal to produce an RF output, and at least one amplifier for amplifying the RF output for transmission; and the receive path comprising at least one second amplifier for amplifying a received RF input, at least one second frequency synthesizer for generating a second synthesized RF signal, at least one second mixer for mixing the amplified RF input with the second synthesized RF signal to produce a baseband signal, at least one second filter for filtering the baseband signal, and at least one analogue to digital converter for converting the baseband signal to a digital output signal, at least one switch arrang

Abstract: An RF transceiver apparatus comprises transmitter circuitry arranged to convert signals from a baseband frequency to RF transmission frequencies and receiver circuitry arranged to convert signals from RF reception frequencies to the baseband frequency. The transmitter and receiver circuitry each comprise three mixers arranged to convert a signals between the baseband frequency, a first intermediate frequency; a second intermediate frequency that is higher than the transmission frequencies; and a second intermediate frequency to the transmission frequency.

Abstract: An RF transceiver apparatus comprises transmitter circuitry arranged to convert signals from a baseband frequency to RF transmission frequencies and receiver circuitry arranged to convert signals from RF reception frequencies to the baseband frequency. The transmitter and receiver circuitry each comprise three mixers arranged to convert a signals between the baseband frequency, a first intermediate frequency; a second intermediate frequency that is higher than the transmission frequencies; and a second intermediate frequency to the transmission frequency.

Abstract: A loading arrangement for an input stage of a source coupled logic gate comprises a loading element having at least one resistive element and at least one voltage limiting element connected in parallel with one another. There is also disclosed a loading arrangement comprising resistive and voltage limiting elements connected in parallel.