Abstract: The invention produces an accurate quadrature relationship for a range of frequencies using passive components in the primary quadrature splitting circuits. A reference oscillator (202) generates a reference signal which is fed to a conventional passive quadrature splitter circuit (204). However, since the reference circuit provides signals over a range of frequencies, the output signals of the passive quadrature splitter may not have an accurate quadrature relationship. The output signals of the passive quadrature splitter are then equalized in magnitude, and the sum and difference of the signals are produced, which will be in an accurate quadrature relationship.

Abstract: A differential circuit (200) provides for reverse isolation between input and output ports (202, 204). The differential circuit has amplification circuitry that includes active transistors (221, 222) and reverse isolation circuitry that employ transistors (223,224) having similar manufacturing and processing characteristics to couple the input and output ports (202, 204).

Abstract: An apparatus (100) includes a differential processing circuit (135) responsive to an input signal with first and second signal components, and a signal imbalance suppressor (130) that preprocesses the input signal, prior to input to the differential processing circuit, to remove amplitude and/or phase imbalances that exist between the first and second signal components, in order to reduce even order distortion generation within the differential processing circuit.

Abstract: A parameter extraction technique for an electrical structure is based on a definition of network parameters that isolates pure mode responses of the electrical structure, and that makes mode conversion responses of the electrical structure negligible. A set of network parameters is obtained that represents pure mode responses for the electrical structure (410). These network parameters are processed to obtain model parameters that characterize each pure mode response (422, 424, 426, 428, 432, 434, 436, 438). Preferably, the mode specific parameters to combined to obtain mode independent parameters, such as coupling factor, propagation constant, and characteristic impedance values (440, 450).

Abstract: A three-dimensional inductor coil is fabricated on top of a semiconductor substrate. The fabrication process includes the steps of depositing a first photoresist layer (406), forming a trench therein, and filling the trench with electroplated metal (404). A second photoresist layer (408) is deposited, and first and second trenches (410) are formed therein and filled with electroplated metal (412). A third photoresist layer (416) is deposited and a trench (418) formed therein, and then filled with electroplated metal (420). The first, second, and third photoresist layers (406, 408, 416) are then removed to expose a multi-loop inductor coil (500, 550).

Abstract: A compensated signal source (210, 220) utilizes baseband signals and a radio frequency carrier signal to generate a set of source output signals (226, 227) which are coupled to a particular circuit (230, 240, 250). The signal source (210, 220) is operable in a characterizing mode in which a test configuration is applied, and outputs from the signal source and the particular circuit measured to develop parameters representing imperfections within the signal source and within the particular circuit. The signal source (210, 220) is operable in a normal mode, in which compensation based on the measured parameters is applied to account for the imperfections. In a preferred embodiment, the particular circuit (230, 240, 250) and compensated signal source (210, 220) form part of an amplifier (200) that implements linear amplification using nonlinear components (LINC) techniques.

Abstract: A receiver (300) includes input (I.sub.in), output (V.sub.out), forward path with filter (104, and 108), and feedback path with error amplifier (112) coupled into the forward path. Coupled to the feedback path is an error signal storage device (408, 508). A control circuit (320) responsive to input signal amplitude couples to the storage device (408, 508) and retrieves stored error signal information for use by the feedback path. During calibration, a forward path stage is stimulated with a plurality of signals of known amplitude to generate outputs (V.sub.out). The outputs are compared to a reference to generate error signals. Error signal values are stored in memory as a function of input signal amplitude. A plurality of error signal values are stored. During operation, stage input signals are detected and compared with the plurality of signals of known amplitude.

Abstract: An apparatus (100) uses power recovery from a combining circuit (125) to improve efficiency. A power combiner (125) generates multiple output signals (127, 133) from a combination of input signals (113, 114). One of the output signals from the power combiner is coupled to a power recovery circuit (135), and energy is recovered and preferably stored for later use.

Abstract: An electronic device (100) includes a regulator (102) for generating an operating voltage. The device (100) also includes at least one component (110) using the operating voltage and requiring a minimum input voltage for proper operation. The device (100) further includes a sensor (115) for sensing the minimum input voltage of the component (110) to produce a minimum operating voltage. Also included in the device (100) is a feedback circuit (116), responsive to the sensor (115), for feeding the minimum operating voltage to the regulator (102) whereby the regulator (102) alters the output voltage to the level of the minimum operating voltage.

Abstract: A power supply (200) includes a VVC (222) which provides for the efficient conversion of voltages with minimum ripple. The doping of the VVC (222) is altered such that most of the energy is delivered to a load (224) at a substantially constant voltage. The VVC (222) is fabricated using such materials as Zirconium Titanate. The VVC (222) has a high capacitance to volume ratio and therefore results in a significant reduction in the overall size of the power supply (200).

Abstract: An electrochemical charge storage device (20) having a voltage discharge profile which is constant for a substantial period of the discharge cycle, which then drops off sharply to full discharge, in a manner more often associated with a battery discharge profile. The electrochemical charge storage device is further characterized by a discharge rate in excess of at least 100 C., and as much as 7000 C. Accordingly, the electrochemical charge storage device is characterized by a battery discharge voltage profile which occurs at substantially capacitor discharge rates.

Abstract: An amplifier (100) has first and second operation modes. The amplifier (100) includes an amplifier input portion (110) and an amplification gain stage. The amplification stage has two gain paths (120, 140) coupled in parallel to the amplifier input portion (110). At least one of the gain paths (120) has an amplification component (121) that in part forms a switch to select between the first and second operation modes.

Abstract: A voltage regulator (200) includes a controller (204) which selectively activates a plurality of switching means (208, 210, 214, and 212) in order to select between a first current loop in which an energy storage device is charged by an input supply and a second loop in which the energy storage device is coupled to the output terminal (242) of the regulator (200). The switching from the second current loop to the first is governed by the controller (204) determining that the loop current in the second loop has reached a predetermined level. A first switching audio amplifier (300) is disclosed which uses the voltage regulator (200) to provide a continuously variable output voltage (318) in order to provide for high quality amplification which is independent of the volume setting. A second audio amplifier (400) includes a converter (436) which provides discrete voltage levels to a full wave bridge in order to provide improved audio output.

Abstract: A transformer (300) includes several layers of substrate (202, 204, 206, 208). Sandwiched between first set of layers (204 and 206) is a runner that forms two interconnected spirals (323 and 324). These spirals run in opposite directions and form two half coils of the transformer primary. Similarly, sandwiched between the second set of layers (204 and 206) is a runner that forms two other interconnected spirals (321 and 322). These spirals run in opposite directions and form two half coils of the transformer secondary. These half coils are magnetically coupled through the substrate (206) which is substantially thinner than the other substrates (204 and 208). Ground layers (210 and 216) discourage horizontal coupling of the electromagnetic flux between the half coils (321, 322, 323, 324), hence improving the vertical flux transfer through the thin layer (206). Components (218) added to the top layer (202) provide for a device, such as an amplifier inclusive of its coupling transformer.

Abstract: A voltage regulator (200) includes a controller (204) which selectively activates a plurality of switching means (208, 210, 214, and 212) in order to select between a first current loop in which an energy storage device is charged by an input supply and a second loop in which the energy storage device is coupled to the output terminal (242) of the regulator (200). The switching from the second current loop to the first is governed by the controller (204) determining that the loop current in the second loop has reached a predetermined level. A first switching audio amplifier (300) is disclosed which uses the voltage regulator (200) to provide a continuously variable output voltage (318) in order to provide for high quality amplification which is independent of the volume setting. A second audio amplifier (400)includes a converter (436) which provides discrete voltage levels to a full wave bridge in order to provide improved audio output.

Abstract: Pulsewidth-modulated amplifier (100) includes a controller (102) which provides for a set of compensated signals (114, 158 and 160). The compensated signals are used for driving a speaker (136). Controller (100) includes a storage area for storing distortion characteristics for the amplifier for a predetermined operational frequency range. The compensated drive signals (114, 158 and 160) help compensate for the electrical non-linear distortions that occur in amplifier (100) and thereby help reduce the output distortion of amplifier (100).

Abstract: An amplifier (1) used with a pulse width modulated signal which improves the efficiency of a low level input signal comprises two or more switching devices (7,9) with common source/drain or emitter/collector connections. The gates or the bases of the devices are independently driven to optimize the efficiency of the various Rds (on) resistance values of the transistors (61, 63, 65, 89, 91, 93) used in the devices. The amplifier is operated so that during the highest output levels, select switching devices (61, 63, 65) are utilized to reduce in series resistance with the load (13). As output power decreases, devices (89, 91, 93) with higher Rds (on) resistance values are activated by a control signal which greatly improves DC to DC conversion efficiency with improved output voltage resolution, dynamic range and reduced electromagnetic interference potential.

Abstract: An audio amplifier (100) switches between a pulsewidth-modulated (PWM) mode to an analog mode when required in order to reduce unwanted EMI when the signals being reproduced fall within a predetermined threshold range such as when reproducing low amplitude signals. Amplifier (100) includes both a pulsewidth-modulator (114) and a low-level analog amplifier (126) coupled to a speaker bridge circuit. When controller (106) determines that the input signal (102) is at a predetermined level, controller (106) selectively applies to the load (164) an analog signal instead of the PWM signal, this provides for improved dynamic range and reduced amplifier produced EMI.

Abstract: An electronic circuit (300) includes first (302) and second (304) variable impedance devices coupled together. The first (302) and second (304) variable impedance devices are designed such that each exhibits a transfer function which is substantially inverse with respect to the other about the operating point of the electronic circuit. This provides for an electronic circuit which exhibits very low distortion characteristics. Circuits such as tunable filters, voltage-controlled oscillators (VCOs), receivers, etc. will benefit from using an electronic circuit (300) which exhibits such low distortion characteristics.

Abstract: To reduce crosstalk in reentrant off-chip RF selectivity, differential circuits (402, 415), transmission lines (423, 424), and off-chip filters (422) are used in a structure that balances the parasitic capacitances associated with all of the differential elements. The structure includes a substrate (409) with a differential generating circuit (402) and a receiving circuit (415). Two differential transmission lines (423, 424), each with constant characteristic impedance, and each with balanced capacitance to ground, both being closely spaced for some distance, couple the circuits (402, 415) to closely spaced terminating pads (403). A ground plane (412) is shared under both transmission lines (423, 424). A second substrate (408) having a reentrant RF path (406) with the first substrate (409) contains an RF function such as a filter or a delay line.