Abstract: A novel apparatus for a low noise, high isolation, all digital transmit buffer gain control mechanism. The gain control scheme is presented in the context of an all digital direct digital-to-RF amplitude converter (DRAC), which efficiently combines the traditional transmit chain functions of upconversion, I and Q combining, D/A conversion, filtering, buffering and RF output amplitude control into a single circuit. The transmit buffer is constructed as an array of NMOS switches. The control logic for each NMOS switch comprises a pass-gate type AND gate whose inputs are the phase modulated output of an all digital PLL and the amplitude control word from a digital control block. Power control is accomplished by recognizing the impairments suffered by a pseudo class E pre-power amplifier (PPA) when implemented in a CMOS process. Firstly, the NMOS switches of the array have significant on resistance and thus can only draw a limited current from the an RF choke when the input waveform is high.

Abstract: A transformer system includes a package substrate having a surface. A plurality of electrically conductive pads are arranged in spaced apart relationship relative to each other on the substrate surface. A first winding is defined by a first electrically conductive path between a first input and a first output, the first electrically conductive path including at least one wire connected between at least one first pad pair of the electrically conductive pads. At least one electrically conductive pad of each first pad pair is at the substrate surface. A second winding is defined by a second electrically conductive path between a second input and a second output, the second electrically conductive path including at least one wire connected between at least one second pad pair of the electrically conductive pads. At least one electrically conductive pad of each second pad pair is at the substrate surface.

Abstract: A transmit filter (100) receives a stream of data symbols (DT_TX) at a baseband symbol clock rate. An available clock (FREF) is used to generate sample points for producing a generating an oversampled signal. The available clock is independent from the baseband symbol clock, and does not need to be an integer multiple of the clock. Upon identifying a start sequence in the data stream, a phase tracking circuit (106) is used to determine a current position relative to the baseband symbol clock. A state circuit (104) stores the last three, or more, data symbols. Based on the last three data symbols (which determines the shape of the curve for the current data symbol) and the current position (which determines the current position on the curve), a filter circuit (108) generates a sample point.

Abstract: A time-to-digital converter (TDC), a system-on-chip including a TDC, a method of phase detection for use in synthesizing a clock signal and a non-linearity corrector for a TDC. In one embodiment, the TDC includes a chain of delay elements configured to receive a clock signal and generate delayed clock signals. Each one of the delay elements includes: (1) a non-inverting buffer configured to delay the clock signal by about twice a delay of an inverter to provide a buffer-delayed clock signal and (2) a first transmission gate coupled to the non-inverting buffer and configured to delay the clock signal by about the delay of an inverter to provide a first gate-delayed clock signal.

Abstract: Methods and apparatus to perform radio frequency (RF) analog-to-digital conversion are described. According to one example, a receiver includes an amplifier to amplify received analog RF signals and a mixer-free circuit for converting the received analog RF signals to digital signals.

Abstract: A technique of improving antialiasing and adjacent channel interference filtering uses cascaded passive IIR filter stages combined with direct sampling and mixing. The methodology and related architecture allows for increased passive IIR filtering without necessitating use of amplifier stages.

Abstract: A novel method and apparatus for a negative contributive offset compensation mechanism for a transmit buffer adapted to compensate for the positive offset generated by higher order sigma-delta modulators used to amplitude modulate the transmit buffer. The positive outputs from the sigma-delta modulator are processed differently than the negative outputs. The inverters associated with the negative outputs in the sigma-delta modulator are removed and the clock signal used to drive the transistors corresponding to the negative outputs is negated or shifted 180 degrees from the clock used to drive the transistors corresponding to the positive outputs. A non-inverted version of the clock is used with the positive outputs and an inverse clock is used with the negative outputs. Use of the inverse clock causes a negative contributive offset to be generated that is added on the second half cycle of each clock. The result is an offset compensated RF output signal having zero offset.

Abstract: A time-to-digital converter (TDC), a system-on-chip including a TDC, a method of phase detection for use in synthesizing a clock signal and a non-linearity corrector for a TDC. In one embodiment, the TDC includes a chain of delay elements configured to receive a clock signal and generate delayed clock signals. Each one of the delay elements includes: (1) a non-inverting buffer configured to delay the clock signal by about twice a delay of an inverter to provide a buffer-delayed clock signal and (2) a first transmission gate coupled to the non-inverting buffer and configured to delay the clock signal by about the delay of an inverter to provide a first gate-delayed clock signal.

Abstract: System and method for increasing the frequency tuning range of a RF/microwave LC oscillator. A preferred embodiment comprises a voltage controlled oscillator (VCO) configured to generate an output signal at a frequency that is dependent upon a magnitude of an input voltage level and an effective inductance of an inductive load and a variable inductor coupled to the VCO. The variable inductor comprises a primary inductor coupled to the VCO to produce a magnetic field based upon a current flowing through the primary inductor and a secondary inductor magnetically coupled to the primary inductor, the secondary inductor to affect the magnitude of the effective inductance of the primary inductor.

Abstract: System and method for providing type-II (and higher order) phase-locked loops (PLLs) with a fast signal acquisition mode. A preferred embodiment comprises a loop filter with a proportional loop gain path (proportional loop gain circuit 1115) and an integral loop gain block (integral loop gain block 1120). The proportional loop gain path is used during signal acquisition to provide large loop bandwidth, hence fast signal acquisition of a desired signal. Then, during the PLL's signal tracking phase, the integral loop gain block is enabled and its output is combined with output from the proportional loop gain path to provide higher order filtering of the desired signal. An offset that may be present due to the use of the proportional loop gain path can be measured and subtracted to help improve signal tracking settling times.

Abstract: System and method for increasing the frequency tuning range of a RF/microwave LC oscillator. A preferred embodiment comprises a voltage controlled oscillator (VCO) configured to generate an output signal at a frequency that is dependent upon a magnitude of an input voltage level and an effective inductance of an inductive load and a variable inductor coupled to the VCO. The variable inductor comprises a primary inductor coupled to the VCO to produce a magnetic field based upon a current flowing through the primary inductor and a secondary inductor magnetically coupled to the primary inductor, the secondary inductor to affect the magnitude of the effective inductance of the primary inductor.

Abstract: Methods and apparatus to provide an auxiliary receive path to support transmitter functions are disclosed. An example transceiver includes an antenna and a duplexer coupled to the antenna. A transmitter is coupled to the duplexer to output a transmit signal at a transmit frequency. A receiver is coupled to the duplexer to receive a received signal at a receiver frequency. A signal processor is coupled to the transmitter and receiver. An auxiliary receiver is communicatively coupled to the signal processor to receive the transmit signal output from the transmitter and send an auxiliary receiver signal to the signal processor. The signal processor adjusts the transmit signal based on the auxiliary receiver signal.

Abstract: A first periodic voltage waveform (20) is downconverted into a second periodic voltage waveform (35, 36). A plurality of temporally distinct samples (SA1, SA2, . . . ) respectively indicative of areas under corresponding fractional cycles of the first voltage waveform are obtained. The samples are obtained in response to a control signal indicative of a code used to produce the first voltage waveform, and the samples are combined to produce the second voltage waveform.

Abstract: A system for reducing phase-noise in a resonant tank circuit. The system includes a single-electron device configured to inject a single electron into the oscillator circuit tank circuit. The system further includes a synchronizer coupled to the single-electron device and configured to cause the single-electron device to inject the single electron into the resonant tank circuit at a phase based on an extreme (maximum or minimum) electrical characteristic output of the resonant tank circuit.

Abstract: A method of manufacturing a parallel redundant array of single-electron devices. The method includes (a) providing a mask for diffusing a plurality of n-doped regions defined by a first set of a plurality of active regions, (b) providing a mask for disposing a plurality of polysilicon gates defined by a second set of a plurality of exposed regions, wherein an offset between a first member of the plurality of the exposed region of the first set differs in offset from a second member of the plurality of the exposed region of the second set, and (c) fabricating the parallel redundant array of single-electron devices as a function of the offset.

Abstract: A method of providing a p-type substrate, disposing a pad oxide layer on the p-type substrate, disposing a nitride layer on the pad oxide layer, forming a nitride window in the nitride layer, disposing a field oxide in the nitride window, disposing a polysilicon gate over the field oxide, and diffusing a n-doped region in the p-type substrate, thereby forming at least one single-electron tunnel junction between the polysilicon gate and the n-doped region.

Abstract: An on-chip receiver sensitivity test mechanism for use in an integrated RF transmitter wherein the transmitter and the receiver share the same oscillator. The mechanism obviates the need to use expensive RF signal generator test equipment with built-in modulation capability and instead permits the use of very low cost external RF test equipment. The invention utilizes circuitry already existing in the transceiver, namely the modulation circuitry and local oscillators to perform sensitivity testing. Tile on-chip LO is used to generate the modulated test signal that otherwise would need to be provided by expensive external RF test equipment with modulation capability. The modulated LO signal is mixed with an externally generated unmodulated CW RF signal to generate a modulated signal at IF which is subsequently processed by the remainder of the receiver chain. The recovered data bits are compared using an on-chip BER meter or counter and a BER reading is generated.

Abstract: An on-chip receiver sensitivity test mechanism for use in an integrated RF transmitter wherein the transmitter and the receiver share the same oscillator. The mechanism obviates the need to use expensive RF signal generator test equipment with built-in modulation capability and instead permits the use of very low cost external RF test equipment. The invention utilizes circuitry already existing in the transceiver, namely the modulation circuitry and local oscillator, to perform sensitivity testing. The on-chip LO is used to generate the modulated test signal that otherwise would need to be provided by expensive external RF test equipment with modulation capability. The modulated LO signal is mixed with an externally generated unmodulated CW RF signal to generate a modulated signal at IF which is subsequently processed by the remainder of the receiver chain. The recovered data bits are compared using an on-chip BER meter or counter and a BER reading is generated.

Abstract: A transformer system includes a package substrate having a surface. A plurality of electrically conductive pads are arranged in spaced apart relationship relative to each other on the substrate surface. A first winding is defined by a first electrically conductive path between a first input and a first output, the first electrically conductive path including at least one wire connected between at least one first pad pair of the electrically conductive pads. At least one electrically conductive pad of each first pad pair is at the substrate surface. A,second winding is defined by a second electrically conductive path between a second input and a second output, the second electrically conductive path including at least one wire connected between at least one second pad pair of the electrically conductive pads. At least one electrically conductive pad of each second pad pair is at the substrate surface.

Abstract: A novel method and apparatus for defining process variation in a digital RF processor (DRP). The invention is well suited for use in highly integrated system on a chip (SoC) radio solutions that incorporate a very large amount of digital logic circuitry. The method and apparatus provide direct measurement of fabrication process variation in circuits without requiring any additional test equipment by utilizing a time to digital converter (TDC) circuit already present in the chip. The TDC circuit relies on the time delay in an inverter chain to sample a high speed CKV clock using a slow FREF clock. Calculation of inverse time provides a direct correlation for fabrication process variation in each die.