The invention relates to a radio frequency oscillator, the radio frequency oscillator comprising a resonator circuit being resonant at an excitation of the resonator circuit in a differential mode and at an excitation of the resonator circuit in a common mode, wherein the resonator circuit has a differential mode resonance frequency at the excitation in the differential mode, and wherein the resonator circuit has a common mode resonance frequency at the excitation in the common mode, a first excitation circuit being configured to excite the resonator circuit in the differential mode to obtain a differential mode oscillator signal oscillating at the differential mode resonance frequency, and a second excitation circuit being configured to excite the resonator circuit in the common mode to obtain a common mode oscillator signal oscillating at the common mode resonance frequency.

The invention relates to a resonator circuit, the resonator circuit comprising a transformer comprising a primary winding and a secondary winding, wherein the primary winding is inductively coupled with the secondary winding, a primary capacitor being connected to the primary winding, the primary capacitor and the primary winding forming a primary circuit, and a secondary capacitor being connected to the secondary winding, the secondary capacitor and the secondary winding forming a secondary circuit, wherein the resonator circuit has a common mode resonance frequency at an excitation of the primary circuit in a common mode, wherein the resonator circuit has a differential mode resonance frequency at an excitation of the primary circuit in a differential mode, and wherein the common mode resonance frequency is different from the differential mode resonance frequency.

A variable reactance apparatus, tunable oscillator and method for changing a gain associated with an input signal of a tunable oscillator are disclosed. An embodiment of the variable reactance apparatus comprises includes a plurality of unit variable reactance structures comprising including respective control input nodes, and a control circuit configured to connect each of the control input nodes to a respective signal from among a plurality of signals comprising including a first tuning signal and a second tuning signal. An embodiment of a tunable oscillator comprises includes a resonance circuit, a negative impedance structure and a variable reactance apparatus configured for tuning of the oscillator. An embodiment of a method comprises includes altering connections of first and second tuning signals to control input nodes of respective first and second sets of unit variable reactance structures while holding constant a sum of the number of unit variable reactance structures in the first and second sets.

A switchable element, a device and a method for analogue and programmable computing operating on electromagnetic waves having a frequency, wherein the switchable element is configured to configured to, in response to an activation signal, switch from having a first dielectric permittivity for electromagnetic waves having a frequency to having a second dielectric permittivity for electromagnetic waves having the frequency, and the device comprises a plurality of the switchable elements that are adapted to be switched individually in accordance with the computing operation.

A voltage controlled oscillator (VCO) and buffer circuit includes a voltage controlled oscillator (VCO), a buffer circuit configured to receive a signal generated by the VCO, the buffer circuit comprising a first transistor having a parasitic gate-source capacitance (Cgs), and a second transistor coupled across the first transistor, wherein a gate of the first transistor is coupled to a drain and a source of the second transistor, and a gate of the second transistor is coupled to a source of the first transistor.

Embodiments of oscillator circuits for wireless transmission of data are disclosed herein. In one example, an oscillator circuit includes an active network and a passive differential network coupled to the active network is disclosed. The active network is configured to generate an active signal for sustaining oscillation of the oscillator circuit. The passive network includes a first subnetwork, a second subnetwork, a first inductor and a second inductor. The first subnetwork is configured to adjust a central value of a resonant frequency of the oscillation. The passive network further includes a second subnetwork configured to further adjust the resonant frequency of the oscillation.

Embodiments of voltage-controlled oscillators for wireless transmission of data are disclosed herein. In one example, an oscillator circuit includes an active network, a passive differential network coupled to the active network, and a tail tank connected to the active network through a low impedance point of the active network is disclosed. The active network is configured to generate an activating signal for sustaining oscillation of the oscillator circuit. The passive differential network has a first input impedance magnitude peak at a first frequency and a second input impedance magnitude peak at a second frequency. The tail tank circuit has a third input impedance magnitude peak at a third frequency.

A voltage controlled oscillator (VCO) and buffer circuit includes a voltage controlled oscillator (VCO), a buffer circuit configured to receive a signal generated by the VCO, the buffer circuit comprising a first transistor having a parasitic gate-source capacitance (Cgs), and a second transistor coupled across the first transistor, wherein a gate of the first transistor is coupled to a drain and a source of the second transistor, and a gate of the second transistor is coupled to a source of the first transistor.

A method and circuit for linearizing a frequency response of an oscillator controlled by a plurality of capacitor banks are disclosed. In the disclosed method, for each capacitor bank of at least two capacitor banks of the oscillator, a respective sensitivity characteristic of the capacitor bank is determined. Further, a set of reference output frequency control words (FCWs) for an associated set of frequencies of the oscillator are determined. When an input FCW is received and an output FCW is responsively provided based on (i) an interpolation between two reference output FCWs of the set of reference output FCWs and (ii) the respective sensitivity characteristics of the at least two capacitor banks of the oscillator. The output FCW is then applied to the at least two capacitor banks of the oscillator.

A compensation module, an oscillation circuit and associated compensation method for reducing an oscillation frequency variation in an output oscillation signal of a voltage-controlled oscillator (VCO) core are provided. The compensation module includes a compensation circuit and a polarity selection circuit. The compensation circuit has a capacitance value related to voltages of a first and a second receiving terminals. The oscillation frequency variation is changed with the capacitance value. The polarity selection circuit conducts a periodic regulated signal to one of the first receiving terminal and the second receiving terminal. The polarity selection circuit conducts a filtered bias signal to the other of the first receiving terminal and the second receiving terminal. The periodic regulated signal is sensitive to a regulated voltage variation, and the filtered bias signal is insensitive to the regulated voltage variation.