Abstract: The present invention is directed to a comparator circuit for use with in-phase and quadrature phase signals and a method of comparing a resultant vector of the in-phase and quadrature phase signals. In one embodiment, the comparator circuit includes a non-titled comparison circuit that compares a resultant vector of the in-phase and quadrature phase signals to vertical and horizontal comparison boundary member pairs. The comparator circuit also includes a tilted comparison circuit, coupled to the non-tilted comparison circuit, that compares the resultant vector to comparison boundary member diagonals coupled to the vertical and horizontal comparison boundary member pairs. The comparator circuit may still further include a combiner circuit that provides a comparison signal based on signals from the non-tilted and tilted comparison circuits.

Abstract: The present invention is directed to a vector monitor for use with a transmitter employing in-phase and quadrature phase input and feedback signals, and a method of controlling a transmitter. In one embodiment, the vector monitor includes an error detection circuit configured to provide first and second components of an error signal based on the input and feedback signals. Additionally, the vector monitor includes a comparator circuit, coupled to the error detection circuit, configured to compare a resultant vector of the first and second components to a comparison boundary and control a power level of the transmitter based on the comparison.

Abstract: The present invention provides, for use in a radio frequency (RF) transmitter that employs a power amplifier to transmit broadband signals, the power amplifier introducing amplitude and phase distortion, a group delay precompensator circuit. In one embodiment, the group delay precompensator circuit includes: (1) a Cartesian feedback loop coupled between an output of the power amplifier and an input of the RF transmitter; and (2) a group delay compensation block, located in the Cartesian feedback loop, that introduces an opposing phase characteristic into the Cartesian feedback loop and thereby precompensates for the phase distortion. A method of precompensating a group delay and an RF transmitter incorporating the precompensator or the method are also disclosed.

Abstract: The present invention is directed to a comparator circuit for use with in-phase and quadrature phase signals and a method of comparing a resultant vector of the in-phase and quadrature phase signals. In one embodiment, the comparator circuit includes a non-titled comparison circuit that compares a resultant vector of the in-phase and quadrature phase signals to vertical and horizontal comparison boundary member pairs. The comparator circuit also includes a tilted comparison circuit, coupled to the non-tilted comparison circuit, that compares the resultant vector to comparison boundary member diagonals coupled to the vertical and horizontal comparison boundary member pairs. The comparator circuit may still further include a combiner circuit that provides a comparison signal based on signals from the non-tilted and tilted comparison circuits.

Abstract: The present invention is directed to a vector monitor for use with a transmitter employing in-phase and quadrature phase input and feedback signals, and a method of controlling a transmitter. In one embodiment, the vector monitor includes an error detection circuit configured to provide first and second components of an error signal based on the input and feedback signals. Additionally, the vector monitor includes a comparator circuit, coupled to the error detection circuit, configured to compare a resultant vector of the first and second components to a comparison boundary and control a power level of the transmitter based on the comparison.

Abstract: The present invention provides, for use in a radio frequency (RF) transmitter that employs a power amplifier to transmit broadband signals, the power amplifier introducing amplitude and phase distortion, a group delay precompensator circuit. In one embodiment, the group delay precompensator circuit includes: (1) a Cartesian feedback loop coupled between an output of the power amplifier and an input of the RF transmitter; and (2) a group delay compensation block, located in the Cartesian feedback loop, that introduces an opposing phase characteristic into the Cartesian feedback loop and thereby precompensates for the phase distortion. A method of precompensating a group delay and an RF transmitter incorporating the precompensator or the method are also disclosed.

Abstract: An antenna array system combines the antenna signals from separate antennas using at least one delay in the RF path of an antenna. In certain embodiments, the antenna array system combines the antenna signals in the Radio Frequency (RF) domain before analog-to-digital (A/D) conversion, thereby reducing the amount of hardware required when compared to antenna array systems where the antenna signals are combined digitally. In doing so, signals from antennas are combined with signals from a plurality of antennas to determine if they improve signal quality. Only signals determined to improve signal quality are maintained as active. In accordance with other aspects, the antenna system selects parameter settings for the antenna array to provide enhanced performance.

Abstract: An RF detector circuit (28), which may be utilized in an output power control loop (10) for an RF transmitter, includes a bridge circuit (50) including a first arm (52) containing a first diode (D2) which rectifies the RF signal and a second arm (54) which contains a second diode (D3) series-coupled to the first diode (D2), and having an RF bypass capacitor (C4). The second diode (D3) serves as a temperature compensator for the first diode (D2). The outputs of the bridge circuit (50) are connected to the inputs of a differential amplifier circuit (32) which provides a signal for use in the power control loop (10). The detector input signal is derived from the sense output of a directional coupler (22). In a second embodiment the compensating diode (D13) has its cathode coupled to the cathode of the rectifying diode (D12), and the full voltage across the rectifying diode (D12) is applied to the differential amplifier circuit (32).

Abstract: An antenna assembly includes a dipole antenna (D1, D2) and a monopole antenna (C1) having substantially perpendicular polarization directions. The dipole antenna (D1, D2) is provided with a balun (E1, E2) a portion (E1) of which serves as a backplane for a microstrip transmission line (G0, G1, G2) which transmits RF signals. The microstrip transmission line includes a first portion (G0) connected to a coaxial feed cable (F), a second portion (G1) having its ends respectively connected by a first switch (A) to the monopole antenna (C1) and a second switch (B) to the balun portion (E1) and a third portion (G2). When the switches (A, B) are closed to render the monopole antenna (C1) operative, the third portion (G2) serves to detune the dipole antenna (D1, D2). The assembly may be formed as a two-sided printed circuit board.