Abstract: A pilot system and method is disclosed that increases the rate of convergence of the second loop alignment control in a feed forward amplifier. Both a pilot generation and detection system and search algorithm controlling the alignment are disclosed. By measuring the frequency of the generated pilot, phase information regarding the second loop cancellation transfer function can be inferred. Changes in the pilot frequency as the search algorithm makes steps in the second loop alignment indicate errors in the direction of the search. Using this pilot frequency measurement along with the existing log-power measurement of the residual pilot power improves the convergence speed because fewer steps will be made to reach the optimal alignment setting.

Abstract: A system and method for crest factor reduction of OFDM transmission systems using selective sub-carrier degradation, is disclosed. A modulated communications signal comprising a series of symbols is converted into parallel format in groups of plural symbols in the frequency domain. Crest factor reduction reduces a primary peak of the groups of plural symbols by selective sub-carrier degradation, to generate peak reduction symbols. The groups of plural symbols are converted into time domain symbols, and combined with the peak reduction symbols to provide peak reduced symbols in time domain.

Abstract: A dielectric ceramic material as claimed in claim 1 with a composition of formula x CaTiO3+(1?x)SmzRe(1?z)AlO3??(1) optionally doped with about 0.005% to about 5% of CeO2 as a dopant, wherein 0.5?x?0.9, 0.3?z?0.995, or Re may be selected from a group consisting of La, Pr, Dy, Gd, Y, Er, Ho and mixtures thereof.

Abstract: An improved radio frequency receiver and method enabling the dynamic range of a radio frequency receiver to be extended are disclosed. In the receiver system, the effective received channel power is a combination of the wanted signal level, the noise floor and any in band spurious signals generated from blocking signals present at the input to the receiver system. When this total effective channel power is known, the front end gain is optimized by adaptively minimizing the total effective channel power. Since the wanted input signal power does not vary with the receiver gain setting, this optimizes the noise figure and input intercept point for the presented input signal conditions.

Abstract: A system and method of compensating for the effects of the antenna coupling in on-frequency repeaters, whose input and output signals are the same frequency, are disclosed. The repeater is implemented with internal digitally determined compensation that reduces the effect of the antenna coupling, allowing the forward gain of the repeater to be increased. The real and imaginary components of the forward gain are dithered. The change in the power spectrum of the signal in response to the dithering is used to estimate the residual (uncompensated) feedback coupling.

Abstract: A single pole antenna array architecture provides an azimuth variable beamwidth. The array includes a number of driven radiating elements that are spatially arranged having a pivoting actuator so as to provide a controlled variation of the antenna array's radiation pattern.

Abstract: A control system for a linear feed-forward amplifier, using the ratio of measured spurious energy. Measuring receivers are coupled to two monitoring points to measure the spurious energy content in the error signal and at the main output of a feed-forward amplifier. The control system measures the ratio of these detected spurious, and uses this to optimize the settings of the second loop distortion cancellation. With the addition of an extra monitoring point, the same technique may also be used to control an adaptive predistorter prior to the main amplifier.

Abstract: A method for forming flanged end of an inner conductor of a coaxial resonator at one end of the conductive body. The flange is formed integral to the conductive body by flaring the end of the conductive body. The size and shape of the flange are selected to achieve a desired capacitance surface area for use in a resonator. A combination of expanding tool and calibration tool are used to control the size and shape of the flange that will be formed on the end of the conductive body.

Abstract: A dual polarized broadband base station antenna for wireless communication systems is disclosed. The present invention employs a dual polarized boxed arrangement radiation element with high isolation between polarization channels. Plural radiating elements project outwardly from the surface of a ground plane. The antenna elements are paired dipoles.

Abstract: A system and method for controlling the gain in the forward signal path of a digital predistortion linearizer is disclosed. The loop gain of the predistortion system is driven to unity, where a separately controlled constant-gain observation path allows accurate gain control of the forward path. This is divided into digital gain from the predistortion function and analog gain from a Voltage Variable Attenuator (VVA) in the transmitter. The invention balances the distribution between these two domains in order to maximize dynamic range and minimize noise in the forward signal path. In order to distribute the forward path gain accurately, the characteristic of the VVA must be well known. Since these devices tend to be non-linear, with variable characteristic over temperature and batch, the invention compensates for this non-linear behavior by tracking the varying transfer characteristic of the VVA, giving a predictable local characteristic.

Abstract: A system and method of digitally predistorting a transmitter that has a digital input, up-converter, and a RF amplifier is disclosed. A digital predistorter preferably employs three paths for the digital input signal: a linear path, a memoryless digital predistortion path, and a memory based digital predistortion path. The memoryless path is preferably a look up table (LUT) of gain error corrections indexed to the input magnitude or input power. The linear path is separated to preserve the dynamic range of the system and avoid quantization associated with memoryless LUT correction. The memory based digital predistortion path filters the power envelope, or higher even order modes of the input signal magnitude, employing a hierarchical filter, to produce a gain correction. The input signal is modulated by the gain error corrections produced by the memoryless and memory based paths.

Abstract: A directional coupler with two sensing conductors and a basic coupler and a supplementary coupler corresponding to them. The basic coupler is based on the coupling between a first sensing conductor (421) and the transmission conductor (410), and the supplementary coupler is based on the coupling between a second sensing conductor (422) and the transmission conductor. The sensing conductors are substantially shorter than a quarter wave, because of which the directivity of both the basic and the supplementary coupler is low. The other ends of the sensing conductors are connected to each other and further to the measurement port of the directional coupler. The coupling signals caused by a reverse signal in the connecting point of the sensing conductors are arranged equal by their absolute value but oppositely phased, in which case their sum signal in the measurement port is insignificantly small.

Abstract: An improved vault that facilitates the underground storage of electronic equipment, such as instrumentation for wireless telecommunications antenna systems. The vault preferably includes an air lock cover that prevents the electronic equipment from being submerged under water when the vault floods.

Abstract: An antenna control system for setting the tilt angle of a main lobe of an antenna, in particular of an antenna constituting part of a base station in a mobile cellular communication system, said antenna comprising a plurality of antenna elements and phase shifting means for varying the phase of at least one signal being fed to said antenna elements, wherein adjustment of said phase of said signal is achieved by actuating an operating element, and wherein actuation of said operating element is achieved by operating an operating element actuator. The operating element actuator is coupled to the operating element of the phase shifting means by means of a force field coupling.

Abstract: A directional coupler with two sensing conductors and a basic coupler and a supplementary coupler corresponding to them. The basic coupler is based on the coupling between a first sensing conductor (421) and the transmission conductor (410), and the supplementary coupler is based on the coupling between a second sensing conductor (422) and the transmission conductor. The sensing conductors are substantially shorter than a quarter wave, because of which the directivity of both the basic and the supplementary coupler is low. The other ends of the sensing conductors are connected to each other and further to the measurement port of the directional coupler. The coupling signals caused by a reverse signal in the connecting point of the sensing conductors are arranged equal by their absolute value but oppositely phased, in which case their sum signal in the measurement port is insignificantly small.

Abstract: A method and apparatus of transmitting a communication signal between a radio base station and a radiation element. In one embodiment, the method includes receiving an input signal. Then extracting a data signal from the input signal, the data signal includes values representing operating parameters of devices at the radiation element. And producing a status signal for each device that simulates a feedback signal for the device.

Abstract: An envelope tracking radio frequency (RF) power amplifier having an adaptive envelope signal processing circuit is disclosed. An RF input voltage is sampled by the adaptive envelope signal processing circuit which provides control signals to the power supply which supplies voltages to RF power devices in order to simultaneously satisfy two operating conditions: a) provide best possible efficiency of the power amplifier stages depending on the input signal characteristics and b) provide compensation for RF transistor AM-AM and AM-PM distortion compensation across the power range. In particular, the voltage control provides for constant power amplifier gain across the input signal dynamic range, thus minimizing power amplifier amplitude distortions and extending the useful power amplifier linear dynamic range up to saturation point. The power amplifier thus exhibits better linearity and efficiency than offered by conventional techniques and topologies.

Abstract: A high power, low loss RF strip transmission line coupling structure is provided. It includes a multi-layer printed circuit board (PCB), a top cover and a bottom cover. The top and bottom covers provide the ground reference for the strip transmission line coupling structure. The PCB is fastened to the top and bottom covers and is used for: creating the center conductor of an air dielectric strip transmission line and edge coupler; providing a means to transition from microstrip to air dielectric strip transmission line; supporting the air dielectric strip transmission line; routing of other signals; and passing ground to the top and bottom covers. To create an air dielectric strip transmission line, the PCB material is adequately removed to effectively form a rectangular bar of dielectric and metal layers. This rectangular bar is plated along the edges where the PCB material was removed to ensure that the top and bottom PCB metal layers are at the same potential.

Abstract: The present invention relates to a DC extracting arrangement in a RF filter used for extracting a DC voltage and/or a low frequency signal (DC/Com. signal) superimposed on a RF signal. The DC/Com. signal is extracted using a low pass filter which is arranged inside the first resonator inside the filter. Preferably, the low pass filter is a tubular filter. The invention also relates to a filter housing made from Zinc or Zinc alloy.

Abstract: The invention relates to an arrangement for bypassing a low noise amplifier unit in the front stage of a radio receiver, especially intended for the base stations of mobile communication networks. The front stage includes, in succession, a divider (420), an amplifier unit (430) comprising two parallel, low noise amplifier branches, and a first combiner (450). The by-pass arrangement includes a second combiner (443), by which the halves (E11, E12) of the received signal are combined immediately after the divider before the amplification. A change-over switch (SW) is then used to select either the signal that has propagated through the amplifier unit and then combined (G·E1) or the signal (E1?) that has been directly combined as the output signal of the front stage. Due to the invention, the noise figure of the front stage is improved and the integration of its structure is facilitated.