A near field radio-frequency identification (RFID) probe includes a probe tip comprising a resonant coil configured to communicate with an RFID compatible device at a predetermined resonant frequency. The near field RFID probe further includes a plurality of switch capacitor networks each comprising a capacitor and an RF switch, wherein switching the plurality of switch capacitor networks changes the capacitance of the resonant coil, thereby changing the resonant frequency of the resonant coil. The near field RFID probe further includes a probe control module configured to adjust the resonant frequency of the resonant coil to maintain the predetermined resonant frequency by switching the switch capacitor networks responsive to detecting that the resonant frequency of the resonant coil has deviated from the predetermined resonant frequency.

A near field radio-frequency identification (RFID) probe includes a probe tip comprising a resonant coil configured to communicate with an RFID compatible device at a predetermined resonant frequency. The near field RFID probe further includes a plurality of switch capacitor networks each comprising a capacitor and an RF switch, wherein switching the plurality of switch capacitor networks changes the capacitance of the resonant coil, thereby changing the resonant frequency of the resonant coil. The near field RFID probe further includes a probe control module configured to adjust the resonant frequency of the resonant coil to maintain the predetermined resonant frequency by switching the switch capacitor networks responsive to detecting that the resonant frequency of the resonant coil has deviated from the predetermined resonant frequency.

Systems and methods for performing automatic frequency control are provided. Instead of relying on individual frequency tuners for each channel of a multi-channel receiver system, the present subject matter uses a single frequency tuner for receiving each channel of the multi-channel receiver system. A locked demodulator may be designated as a reference demodulator and frequency offset values associated with the reference demodulator may be applied to other demodulators of the multi-channel receiver. These frequency offset values may be used by individual demodulators of each channel for correcting corresponding frequency offsets.

Methods, apparatus, systems and articles of manufacture are disclosed to measure a resonant sensor based on detection of group delay. An example apparatus includes a modulation manager configured to query the resonant sensor with a modulated signal including a frequency; and a resonance determiner configured to determine a resonance frequency of the resonant sensor based on a group delay associated with the resonant sensor and the frequency.

Methods, apparatus, systems and articles of manufacture are disclosed to measure a resonant sensor based on detection of group delay. An example apparatus includes a modulation manager configured to query the resonant sensor with a modulated signal including a frequency; and a resonance determiner configured to determine a resonance frequency of the resonant sensor based on a group delay associated with the resonant sensor and the frequency.

A near field radio-frequency identification (RFID) probe includes a probe tip comprising a resonant coil configured to communicate with an RFID compatible device at a predetermined resonant frequency. The near field RFID probe further includes a plurality of switch capacitor networks each comprising a capacitor and an RF switch, wherein switching the plurality of switch capacitor networks changes the capacitance of the resonant coil, thereby changing the resonant frequency of the resonant coil. The near field RFID probe further includes a probe control module configured to adjust the resonant frequency of the resonant coil to maintain the predetermined resonant frequency by switching the switch capacitor networks responsive to detecting that the resonant frequency of the resonant coil has deviated from the predetermined resonant frequency.

A near field radio-frequency identification (RFID) probe includes a probe tip comprising a resonant coil configured to communicate with an RFID compatible device at a predetermined resonant frequency. The near field RFID probe further includes a plurality of switch capacitor networks each comprising a capacitor and an RF switch, wherein switching the plurality of switch capacitor networks changes the capacitance of the resonant coil, thereby changing the resonant frequency of the resonant coil. The near field RFID probe further includes a probe control module configured to adjust the resonant frequency of the resonant coil to maintain the predetermined resonant frequency by switching the switch capacitor networks responsive to detecting that the resonant frequency of the resonant coil has deviated from the predetermined resonant frequency.

Disclosed is a method and a radio network node for compensating for local oscillator pulling or pushing. The method comprises determining, in a digital domain, a correction phase for the local oscillator to offset a phase error caused by the local oscillator pulling or pushing. The method also comprises correcting a phase of the baseband signal in the digital domain using the correction phase to compensate for the local oscillator pulling or pushing With the proposed method and radio network node, the phase error caused by the local oscillator pulling or pushing could be diminished due to phase correction in the digital domain.

Disclosed is a method and a radio network node for compensating for local oscillator pulling or pushing. The method comprises determining, in a digital domain, a correction phase for the local oscillator to offset a phase error caused by the local oscillator pulling or pushing. The method also comprises correcting a phase of the baseband signal in the digital domain using the correction phase to compensate for the local oscillator pulling or pushing With the proposed method and radio network node, the phase error caused by the local oscillator pulling or pushing could be diminished due to phase correction in the digital domain.

Systems and methods for performing automatic frequency control are provided. Instead of relying on individual frequency tuners for each channel of a multi-channel receiver system, the present subject matter uses a single frequency tuner for receiving each channel of the multi-channel receiver system. A locked demodulator may be designated as a reference demodulator and frequency offset values associated with the reference demodulator may be applied to other demodulators of the multi-channel receiver. These frequency offset values may be used by individual demodulators of each channel for correcting corresponding frequency offsets.