In some examples, a device includes a nano-scale oscillator that exhibits chaotic oscillation responsive to a control input to the nano-scale oscillator, where the control input including a tunable input parameter.

In some examples, a device includes a nano-scale oscillator that exhibits chaotic oscillation responsive to a control input to the nano-scale oscillator, where the control input including a tunable input parameter.

A key based technique that targets obfuscation of critical circuit parameters of an analog circuit block by masking physical characteristics of a transistor (width and length) and the circuit parameters reliant upon these physical characteristics (i.e. circuit biasing conditions, phase noise profile, bandwidth, gain, noise figure, operating frequency, etc.). The proposed key based obfuscation technique targets the physical dimensions of the transistors used to set the optimal biasing conditions. The widths and/or lengths of a transistor are obfuscated and, based on an applied key sequence, provides a range of potential biasing points. Only when the correct key sequence is applied and certain transistor(s) are active, are the correct biasing conditions at the target node set.

Transceiver circuitry for coupling a functional circuit to a transmission medium includes a transmit path for coupling between the functional circuit and the transmission medium, a receive path for coupling between the transmission medium and the functional circuit, and clock generation circuitry coupled to at least one of the transmit path and the receive path. The clock generation circuitry includes an oscillator having transconductance circuitry, a capacitance element coupled in parallel with the transconductance circuitry, a plurality of inductors coupled in parallel with the transconductance circuitry and the capacitance element, and with each other, and a current source coupled to the plurality of inductors. The capacitance element may be variable. An even number of inductors are arranged so that half of the inductors generate magnetic flux in a first direction, and half of the inductors generate magnetic flux in a second direction opposite to the first direction.

Transceiver circuitry for coupling a functional circuit to a transmission medium includes a transmit path for coupling between the functional circuit and the transmission medium, a receive path for coupling between the transmission medium and the functional circuit, and clock generation circuitry coupled to at least one of the transmit path and the receive path. The clock generation circuitry includes an oscillator having transconductance circuitry, a capacitance element coupled in parallel with the transconductance circuitry, a plurality of inductors coupled in parallel with the transconductance circuitry and the capacitance element, and with each other, and a current source coupled to the plurality of inductors. The capacitance element may be variable. An even number of inductors are arranged so that half of the inductors generate magnetic flux in a first direction, and half of the inductors generate magnetic flux in a second direction opposite to the first direction.

A differential Colpitts voltage-controlled oscillator according to example embodiments includes a feedback circuit constituting a Colpitts oscillator structure, a negative resistance circuit including a first negative resistance transistor and a second negative resistance transistor cross-coupled to each other and connected to the feedback circuit, a resonance circuit including a first inductor and a variable capacitor connected to both ends of the first inductor to generate differential output signals base on outputs of the feedback circuit, and a phase noise reduction circuit coupled to the feedback circuit to remove phase noise.

A voltage controlled oscillator comprises a negative resistance, a first inductor, a fixed capacitor, and a frequency control component. The frequency control component comprises at least one varactor and at least a second inductor connected in series with the at least one varactor. A magnitude of an inductance of the second inductor is selected such that the frequency control component has an effective capacitance range larger than a capacitance range of the at least one varactor.

A voltage controlled oscillator comprises a negative resistance, a first inductor, a fixed capacitor, and a frequency control component. The frequency control component comprises at least one varactor and at least a second inductor connected in series with the at least one varactor. A magnitude of an inductance of the second inductor is selected such that the frequency control component has an effective capacitance range larger than a capacitance range of the at least one varactor.

The invention discloses a voltage controlled oscillator (VCO) based on hybrid resonator, including a hybrid resonator and a negative resistance circuit, wherein the hybrid resonator includes the first LC series resonance branch, the second LC series resonance branch and the third LC series resonance branch. The first LC series resonance branch and the second LC series resonance branch forms a parallel structure, in which one end of the said parallel structure is grounded while the other end is connected to the third LC series resonance branch, and the other end of the third LC series resonance branch is connected to the negative resistance circuit. The resonance frequency of the first LC series resonance branch is lower than that of the second LC series resonance branch. The invented VCO can effectively improve the phase noise, especially maintain a good phase noise with the increase of the tuning frequency.

The invention discloses a voltage controlled oscillator (VCO) based on hybrid resonator, including a hybrid resonator and a negative resistance circuit, wherein the hybrid resonator includes the first LC series resonance branch, the second LC series resonance branch and the third LC series resonance branch. The first LC series resonance branch and the second LC series resonance branch forms a parallel structure, in which one end of the said parallel structure is grounded while the other end is connected to the third LC series resonance branch, and the other end of the third LC series resonance branch is connected to the negative resistance circuit. The resonance frequency of the first LC series resonance branch is lower than that of the second LC series resonance branch. The invented VCO can effectively improve the phase noise, especially maintain a good phase noise with the increase of the tuning frequency.