Abstract: A circuit for a voltage controlled oscillator (VCO) buffer is described. The circuit includes a first capacitor connected to an input of the VCO buffer that is connected to a VCO core. The circuit also includes a second capacitor connected to the input of the VCO buffer and the gate of a p-type metal-oxide-semiconductor field effect (PMOS) transistor. The circuit further includes a first switch connected to the first capacitor and the gate of the PMOS transistor. The circuit also includes a third capacitor connected to the input of the VCO buffer. The circuit further includes a fourth capacitor connected to the input of the VCO buffer and the gate of an n-type metal-oxide-semiconductor field effect (NMOS) transistor. The circuit also includes a second switch connected to the third capacitor and the gate of the NMOS transistor.

Abstract: An oscillator includes a resonator, a first and a second p-type transistor, and a first and a second n-type transistor. The resonator has a first terminal and a second terminal. The first p-type transistor is switchably connected to the first terminal while the second p-type transistor is switchably connected to the second terminal. A first drain of the first n-type transistor and the second drain of the second n-type transistor are electrically connected to the first terminal and the second terminal, respectively. The oscillator is capable of operating in an NMOS only mode and in a CMOS mode.

Abstract: Exemplary embodiments are directed to a programmable varactor device. A varactor device may include an input device configured to receive a tuning voltage and generate a bias voltage at least partially dependent on the tuning voltage. The varactor device may also include a varactor pair coupled to the input device and having a first variable capacitor and a second variable capacitor, wherein each of the first variable capacitor and a second variable capacitor are configured for operable coupling to each of the bias voltage and the tuning voltage.

Abstract: A wideband frequency generator has two or more oscillators for different frequency bands, disposed on the same die within a flip chip package. Coupling between inductors of the two oscillators is reduced by placing one inductor on the die and the other inductor on the package, separating the inductors by a solder bump diameter. The loosely coupled inductors allow manipulation of the LC tank circuit of one of the oscillators to increase the bandwidth of the other oscillator, and vice versa. Preventing undesirable mode of oscillation in one of the oscillators may be achieved by loading the LC tank circuit of the other oscillator with a large capacitance, such as the entire capacitance of the coarse tuning bank of the other oscillator. Preventing the undesirable mode may also be achieved by decreasing the quality factor of the other oscillator's LC tank and thereby increasing the losses in the tank circuit.

Abstract: A capacitance switching element includes first and second capacitors connected in series by transistors. The gates of the transistors are biased by a first signal through one set of resistors, and the sources and drains are biased by a second signal through a second set of resistors. The signals are level-shifted and may be complimentary. To turn the element ON, the first signal may be set to VDD and the second signal may be set to zero. To turn the element OFF, the first signal may be set to a multiple of VDD/2 and the second signal may be set to the multiple plus one of VDD/2. When the element is used in an oscillator tuning circuit, the voltage stress on the transistors is reduced and the transistors may be fabricated with thin oxide. The oscillator may be used in a transceiver of a cellular access terminal.

Abstract: Techniques for calibrating digitally controlled oscillators (DCOs) are disclosed. In an aspect of the disclosure, an initial set of control codes for operating the DCO is determined. A range of output frequencies produced from the initial set is identified. Gaps or instances of overlap are identified in the frequency range. For the overlap case, control codes are removed from the initial set that correspond to the overlap instance to establish a revised set. For the gap case, control codes are added to the initial set for producing frequencies values that fill the gap. An apparatus for performing the same is also disclosed.

Abstract: Techniques for calibrating digitally controlled oscillators (DCOs) are disclosed. In an aspect of the disclosure, an initial set of control codes for operating the DCO is determined. A range of output frequencies produced from the initial set is identified. Gaps or instances of overlap are identified in the frequency range. For the overlap case, control codes are removed from the initial set that correspond to the overlap instance to establish a revised set. For the gap case, control codes are added to the initial set for producing frequencies values that fill the gap. An apparatus for performing the same is also disclosed.