Abstract: A communication receiver amplifies a pulse-amplitude-modulated (PAM) signal representing an integer-valued sequence of first data elements (D1) with an adjustable first gain (G1) and digitizes the amplified signal to produce a sequence of second data elements (D2) representing successive magnitudes of the PAM signal. A first automatic gain control (AGC) circuit determines the rate at which magnitudes of the second data sequence elements fall within a first range and adjusts G1 to maintain that rate within a second range. Digital signal processing circuits within the receiver process the second data to produce a sequence of third data elements (D3), each having a real number value substantially equal to a product of a second gain G2 and a corresponding one of the first data elements D1. A slicer rounds the real number represented by each third data sequence element to produce a corresponding integer-valued element of a fourth data sequence (D4).

Abstract: Interconnected master and slave transceivers provide data communication between host computers. Each transceiver receives and encodes elements of a first data sequence from its local host computer at a first rate and employs a finite impulse response (FIR) filter to interpolate elements of the encoded first data sequence to produce elements of a second data sequence at a higher second rate controlled by a local clock signal. The second data sequence controls the amplitude of an analog signal sent to the other transceiver. Each transceiver also processes the analog signal arriving from the other transceiver to produce elements of a third data sequence at that second rate and employs a second FIR filter for Interpolating the third data sequence to produce elements of a fourth data sequence at the slower first rate. Fourth data sequence elements are then decoded to produce elements of a fifth sequence forwarded to the local host computer at the first rate.

Abstract: A 1000BASE-T transceiver linked to an unshielded twisted pair (UTP) through a transformer currently transmits and receives outgoing and incoming signals via the UTP. The transceiver employs an energy efficient class B or AB line driver supplying asymmetric output currents to the transformer's primary winding terminals so that the transformer's secondary winding induces the outgoing signal on the UTP. Resistors couple the transformer's primary winding terminals to inputs of separate amplifiers producing a differential output signal mimicking the incoming 1000BASE-T signal. Since both the incoming and outgoing signals contribute to voltages appearing at the transformer's primary winding terminals, echo cancellation circuits provide additional compensating signals to the amplifier inputs for canceling echo in each amplifier input due to the resistive and reactive loading on each driver output current and arising from the asymmetric nature of the class B or AB driver's output currents.

Abstract: Interconnected master and slave transceivers provide data communication between host computers. Each transceiver receives and encodes elements of a first data sequence from its local host computer at a first rate and employs a finite impulse response (FIR) filter to interpolate elements of the encoded first data sequence to produce elements of a second data sequence at a higher second rate controlled by a local clock signal. The second data sequence controls the amplitude of an analog signal sent to the other transceiver. Each transceiver also processes the analog signal arriving from the other transceiver to produce elements of a third data sequence at that second rate and employs a second FIR filter for interpolating the third data sequence to produce elements of a fourth data sequence at the slower first rate. Fourth data sequence elements are then decoded to produce elements of a fifth sequence forwarded to the local host computer at the first rate.

Abstract: A 1000BASE-T transceiver linked to an unshielded twisted pair (UTP) through a transformer currently transmits and receives outgoing and incoming signals via the UTP. The transceiver employs an energy efficient class B or AB line driver supplying asymmetric output currents to the transformer's primary winding terminals so that the transformer's secondary winding induces the outgoing signal on the UTP. Resistors couple the transformer's primary winding terminals to inputs of separate amplifiers producing a differential output signal mimicking the incoming 1000BASE-T signal. Since both the incoming and outgoing signals contribute to voltages appearing at the transformer's primary winding terminals, echo cancellation circuits provide additional compensating signals to the amplifier inputs for canceling echo in each amplifier input due to the resistive and reactive loading on each driver output current and arising from the asymmetric nature of the class B or AB driver's output currents.

Abstract: A communication receiver amplifies a pulse-amplitude-modulated (PAM) signal representing an integer-valued sequence of first data elements (D1) with an adjustable first gain (G1) and digitizes the amplified signal to produce a sequence of second data elements (D2) representing successive magnitudes of the PAM signal. A first automatic gain control (AGC) circuit determines the rate at which magnitudes of the second data sequence elements fall within a first range and adjusts G1 to maintain that rate within a second range. Digital signal processing circuits within the receiver process the second data to produce a sequence of third data elements (D3), each having a real number value substantially equal to a product of a second gain G2 and a corresponding one of the first data elements D1. A slicer rounds the real number represented by each third data sequence element to produce a corresponding integer-valued element of a fourth data sequence (D4).

Abstract: A non-uniform analog-to-digital converter (ADC) produces digital output data representing the magnitude of an analog input signal having a non-uniform magnitude probability distribution. The digital output data represents the analog input signal with relatively high resolution for the input signal's more frequently occurring magnitudes and with relatively lower resolution for the input signals less frequently occurring magnitudes.

Abstract: A low-profile antenna includes a ground-plane element defining a ground plane and an elongated radiator element configured and disposed in relation to the ground plane to define a vertical loop when the ground plane is horizontally disposed. A substantial broad segment of the radiator element is parallel to the ground plane. One end of the radiator element is connected to the ground-plane element and another end of the radiator element having spaced-apart legs with feet is capacitively coupled to the ground-plane element by dielectric spacing elements that are disposed between the feet of the radiator element and the ground-plane element. A conductive-material layer contacts the feet between the feet and the dielectric spacing element. An exposed portion of the conductive-material layer that extends from beneath the feet of the radiator element includes removal tabs for enabling the capacitive coupling to be adjusted by removing at least some of the exposed tabs.