Abstract: A transimpedance amplifier (TIA) device design is disclosed. Symmetric components include first and second resistors Ri, Rfb, Re, Rm, Rx, Rc, and Rl, and transistors Q1-Q4. An optional mixer or cascode adds transistors Q5-Q8. Values for resistor components Rx provide extended feedback gain tuning in a TIA-based current amplifier or mixer implementations without greatly affecting the input impedance or requiring more attenuators. Example values for resistor components Rx range from about 50 to about 350 ohms.

Abstract: A device for phase adjustment preset for an N-path filter comprising a logic block; a ring divider array creating a local oscillator drive for a mixer; the ring divider array comprising: a plurality of registers, each comprising: inputs S, R, D, and clock, and output Q; the plurality of registers comprising at least: a first register; a second register; and an Nth register; a preset control word; wherein the preset control word is applied to the logic block, the logic block providing input to each of the S and the R inputs of each the register; whereby a desired starting phase of the divider is controlled. A method includes defining a desired starting conditions; determining a control word from desired starting conditions; applying control word to logic block; applying a reset signal to logic block; and outputting values for each of S and R to each register.

Abstract: The system and method for adaptively obtaining coefficients of an inverse model for both equalization and pre-distortion for a multi-channel and reconfigurable RF system. The system preforms real-time learning and adaption and does not require training sets. In some cases, the system learns new coefficients across time and transient changes in performance.

Abstract: A variable gain amplifier circuit including a first amplifier, a second amplifier, and a variable capacitor connected in series between the first amplifier and the second amplifier is disclosed. As a gain of the variable gain amplifier circuit varies, the input impedance, output impedance, noise figure and third-order output intercept point (OIP3) of the variable gain amplifier circuit remain unchanged.

Abstract: A variable gain amplifier circuit including a first amplifier, a second amplifier, and a variable capacitor connected in series between the first amplifier and the second amplifier is disclosed. As a gain of the variable gain amplifier circuit varies, the input impedance, output impedance, noise figure and third-order output intercept point (OIP3) of the variable gain amplifier circuit remain unchanged.

Abstract: The system and method for adaptively obtaining coefficients of an inverse model for both equalization and pre-distortion for a multi-channel and reconfigurable RF system. The system preforms real-time learning and adaption and does not require training sets. In some cases, the system learns new coefficients across time and transient changes in performance.

Abstract: Techniques are provided for phase-locked loop (PLL) configuration, based on a calibrated lookup table (LUT). A methodology implementing the techniques according to an embodiment includes selecting one of a number of voltage controlled oscillators (VCOs) of the PLL, and selecting a tuning parameter to control the VCO. The method further includes testing the PLL, using multiple loop divider values, to determine a minimum and maximum value that define the lower and upper bounds of a range of loop divider values for which the PLL achieves a locked state while using the selected VCO and tuning parameter. The method further includes storing PLL configuration parameters to an entry in the configuration LUT, the PLL configuration parameters to include an identification of the selected VCO, the selected tuning parameter, the minimum loop divider value, and the maximum loop divider value. The method iterates using additional combinations of selected VCOs and tuning parameters.

Abstract: An analog transceiver having low latency for processing a received RF/MW signal and modifying the received RF/MW signal into a modified RF/MW signal prior to transmission of the modified RF/MW signal. The analog transceiver comprises a receiving antenna; a direct conversion receiver, coupled with the receiving antenna, for splitting the received RF/MW signal into an in-phase portion and a quadrature portion; an analog signal processing device, having a plurality of actuatable switches, for modifying the in-phase and quadrature portions and outputting modified signals while only introducing minimal latency during processing; a direct conversion transmitter, for receiving the suitably modified in-phase and quadrature portions and forming the modified RF/MW signal; and a transmitting antenna for receiving the modified RF/MW signal and transmitting the modified RF/MW signal.

Abstract: Techniques for performing built-in self-test (BIST) of performance of an RF system are disclosed. The techniques may be used, for example, for measuring distortion generated by the RF system under test, detecting faults in the system, determining calibration of the system, and/or assisting in compensating analog circuitry that is sensitive to temperature, supply voltage, and/or process variations. Also, a BIST architecture for determining RF performance of an RF systems is disclosed.

Abstract: A feedforward linearizer device is disclosed. The device includes a main amplifier, and a linearizing amplifier operatively coupled to the main amplifier. A first reference generator is operatively coupled to the main amplifier by a first reference node. A second reference generator is operatively coupled to the linearizing amplifier by a second reference node, and is configured to cause an optimal linearizing amplifier output current for each of a plurality of temperatures. In one such case, the second reference generator is configured to cause an optimal linearizing amplifier output current for each of a plurality of temperatures based on a corresponding optimal ratio of main amplifier output current and linearizing amplifier output current. The linearizing amplifier may be configured with a tunable current source that is controlled by the second reference generator, or a current source having a fixed total transistor area (not tunable).

Abstract: Techniques for performing built-in self-test (BIST) of performance of an RF system are disclosed. The techniques may be used, for example, for measuring distortion generated by the RF system under test, detecting faults in the system, determining calibration of the system, and/or assisting in compensating analog circuitry that is sensitive to temperature, supply voltage, and/or process variations. Also, a BIST architecture for determining RF performance of an RF systems is disclosed.

Abstract: A feedforward linearizer device is disclosed. The device includes a main amplifier, and a linearizing amplifier operatively coupled to the main amplifier. A first reference generator is operatively coupled to the main amplifier by a first reference node. A second reference generator is operatively coupled to the linearizing amplifier by a second reference node, and is configured to cause an optimal linearizing amplifier output current for each of a plurality of temperatures. In one such case, the second reference generator is configured to cause an optimal linearizing amplifier output current for each of a plurality of temperatures based on a corresponding optimal ratio of main amplifier output current and linearizing amplifier output current. The linearizing amplifier may be configured with a tunable current source that is controlled by the second reference generator, or a current source having a fixed total transistor area (not tunable).

Abstract: Techniques are disclosed for reducing off-state leakage current in a differential switching device. The techniques can be embodied, for example, in a method that includes receiving a differential input signal at a differential input of each of a primary switch and a dummy switch. In an enabled-state of the device, the method further includes passing the differential input signal to a differential output of the primary switch. In a disabled-state of the device, the method further includes canceling off-state leakage current at the differential output of the primary switch, by virtue of the dummy switch having its differential output reverse-coupled to the differential output of the primary switch. The method may further include preventing the dummy switch from passing signals other than off-state leakage signals. The techniques can be embodied, for instance, in a switching device.

Abstract: Techniques are disclosed that allow for programmable attenuation using thermometer code steps. By thermometer coding the attenuator structure, monotonicity is guaranteed or otherwise greatly improved, which eliminates instability problems with automatic gain control loops and without the need for compensation or trimming. In addition, the thermometer coding technique also greatly reduces phase discontinuity between adjacent gain states.

Abstract: A Gilbert cell mixer design is disclosed. Instead of using a differential transconductance stage as typically done, the design employs a differential transimpedance amplifier input stage. By utilizing a transimpedance input stage to the Gilbert mixer, feedback is used to obtain higher linearity without sacrificing noise performance. The transimpedance input stage supplies a current signal to the cascode connected Gilbert switching quad, so the transimpedance amplifier output is taken from the collector of the transimpedance amplifier output transistor, instead of the emitter as normally done with transimpedance amplifiers.

Abstract: Techniques are disclosed that allow for programmable attenuation using thermometer code steps. By thermometer coding the attenuator structure, monotonicity is guaranteed or otherwise greatly improved, which eliminates instability problems with automatic gain control loops and without the need for compensation or trimming. In addition, the thermometer coding technique also greatly reduces phase discontinuity between adjacent gain states.

Abstract: Techniques are disclosed that allow for programmable attenuation using thermometer code steps. By thermometer coding the attenuator structure, monotonicity is guaranteed or otherwise greatly improved, which eliminates instability problems with automatic gain control loops and without the need for compensation or trimming. In addition, the thermometer coding technique also greatly reduces phase discontinuity between adjacent gain states.

Abstract: Receiver power techniques are disclosed that allow for real-time adjustment of receiver dynamic range by virtue of supplied DC power, based on signal strengths currently received by the receiver. The disclosed techniques use real-time monitoring of receiver output to detect the presence of large signals, and to then adjust bias points in the receiver to reduce DC power consumption in the absence of large signals. By adapting the power to the current signal environment by autonomously adjusting the bias points, the mean power consumption of the receiver can be greatly reduced. This in turn has a number of benefits, such as increased battery life, decreased heat, increased circuit lifetime, and decreased noise figure.

Abstract: Techniques are disclosed for reducing off-state leakage current in a differential switching device. The techniques can be embodied, for example, in a method that includes receiving a differential input signal at a differential input of each of a primary switch and a dummy switch. In an enabled-state of the device, the method further includes passing the differential input signal to a differential output of the primary switch. In a disabled-state of the device, the method further includes canceling off-state leakage current at the differential output of the primary switch, by virtue of the dummy switch having its differential output reverse-coupled to the differential output of the primary switch. The method may further include preventing the dummy switch from passing signals other than off-state leakage signals. The techniques can be embodied, for instance, in a switching device.

Abstract: A Gilbert cell mixer design is disclosed. Instead of using a differential transconductance stage as typically done, the design employs a differential transimpedance amplifier input stage. By utilizing a transimpedance input stage to the Gilbert mixer, feedback is used to obtain higher linearity without sacrificing noise performance. The transimpedance input stage supplies a current signal to the cascode connected Gilbert switching quad, so the transimpedance amplifier output is taken from the collector of the transimpedance amplifier output transistor, instead of the emitter as normally done with transimpedance amplifiers.