Abstract: Circuits and methods concerning radio frequency (RF) communication are disclosed. In some example embodiments, an apparatus includes a first antenna providing a signal path, having at least one loop, between a first pair of nodes. The apparatus also includes a second antenna providing a signal path, having one or more loops, between a second pair of nodes. The second antenna is placed sufficiently close to the first antenna to cause the second antenna to resonate in response to an RF signal being applied to the first pair of nodes by a communication circuit.

Abstract: An analysis circuit for analysing the RF response of an RF circuit, includes a voltage controlled oscillator (12), wherein a signal derived from voltage controlled oscillator output is applied as input to the RF circuit (10). A first mixer (18) mixes the RF circuit output with a first mixer signal derived from the voltage controlled oscillator and a second mixer (20) mixes the RF circuit unit output with a second mixer signal derived from the voltage controlled oscillator, the first and second mixer signals being 90 degrees out of phase. The mixer output signals are processed to provide the analysis. This analysis circuit uses mixers to enable baseband digital signal processing of signals to enable a frequency response characteristic of the RF circuit to be obtained. The analysis circuit essentially operates in the manner of an IF demodulator circuit.

Abstract: The present invention discloses an integrated circuit (200) including a module (130) for processing a radio-frequency (RF) signal during normal operation of the integrated circuit. The IC (200) has an on-chip test arrangement for generating an accurate RF test signal for testing the module (130) in a test mode. To this end, the test arrangement comprises a signal source (210) for generating a radio-frequency control signal in the test mode and a complementary transistor pair (230) arranged in series, said pair being coupled between a first supply rail and a second supply rail, and being arranged to generate the radio-frequency test signal on its output in response to the radio-frequency control signal supplied to its control terminals. The invention is based on the realization that if a stable enough supply voltage is provided to the transistor pair, the pair can be forced to produce an accurate rail-to-rail voltage swing at RF frequencies on its output.

Abstract: An analysis circuit for analysing the RF response of an RF circuit, comprises a voltage controlled oscillator (12), wherein a signal derived from voltage controlled oscillator output is applied as input to the RF circuit (10). A first mixer (18) mixes the RF circuit output with a first mixer signal derived from the voltage controlled oscillator and a second mixer (20) mixes the RF circuit unit output with a second mixer signal derived from the voltage controlled oscillator, the first and second mixer signals being 90 degrees out of phase. The mixer output signals are processed to provide the analysis. This analysis circuit uses mixers to enable baseband digital signal processing of signals to enable a frequency response characteristic of the RF circuit to be obtained. The analysis circuit essentially operates in the manner of an IF demodulator circuit.