Dynamic range

About: Dynamic range is a research topic. Over the lifetime, 7576 publications have been published within this topic receiving 101739 citations. The topic is also known as: DNR & DR.

Fast Co-Polar and Cross-Polar 3D Pattern Synthesis With Dynamic Range Ratio Reduction for Conformal Antenna Arrays

Abstract: This paper presents a fast method for conformal antenna arrays that enables the synthesis of 3D co-polar and cross-polar patterns, simultaneously reducing the dynamic range ratio (DRR) of the array excitations. The power synthesis problem is reduced to a field synthesis one by introducing two auxiliary phase patterns: one for the co-polar pattern and the other for the cross-polar pattern. The problem is then iteratively solved with respect to the two auxiliary phase patterns and to the array excitations. A modified version of the method is also proposed, for the particular case where the DRR reduction is not required, obtaining a further strong reduction of the computational time.

Determination of microwave phase and amplitude from power measurements

Abstract: Although straightforward in principle, the extension of existing designs for automatic network analyzers (ANA's) to the higher microwave frequencies is difficult in the current state of the art. What appears to be needed is a basically different approach to the microwave detection problem. One promising alternative is provided by the so-called “six-port” techniques, which eliminate the need for modulation or for frequency conversion, local oscillators, phase detectors, etc. Recent theoretical studies have provided new insights into the basic concept and lead to “five-port” configurations which require three instead of four amplitude detectors. Of particular interest is the projected measurement dynamic range of 50–60 dB corresponding to a dynamic range requirement in the amplitude detectors of a nominal 20 dB or less.

Adaptive quantization method and apparatus for an OFDM receiver

Abstract: A quadrature frequency division multiplexing (“OFDM”) wireless receiver, including methods and devices for adaptive quantization of OFDM signals according to modulation and coding schemes and sub-carrier frequency responses, is provided. Efficient quantization may be utilized to reduce the large dynamic range of signals to achieve circuit simplification and chip area reduction. In one embodiment, a quantization circuit includes a quantization selector to select quantization thresholds according to modulation and coding schemes and sub-carrier frequency responses, and a non-uniform quantizer to reduce input dynamic range so that an output is represented by fewer bits than an input.

Sidelobe blanking system

Abstract: A logarithmetic sidelobe blanking system operable in a pulse compression radar system in which the dynamic range of the blanking system is not limited by the compression dynamic range. A sidelobe blanking receiver is provided to process the sidelobe signals in a manner identical to the processing in the radar receiver. The uncompressed IF pulses in both the sidelobe receiver and the main lobe receiver are sampled prior to their being amplitude limited, and are applied through logarithmetic amplifiers whose dynamic range capability is at least equal to the dynamic range of the preceding circuits. The output signals of the logarithmetic amplifiers are then compared and if the sidelobe signal is larger than the main lobe signal the compressed pulse at the output of the pulse compressor is located and used for blanking to ensure that only the time interval of the compressed pulse width is removed. As sampling is made prior to the threshold or amplitude limiting circuit, the full dynamic range of the receiver is processed. The sidelobe receiver system in accordance with the invention also includes an arrangement for selecting the above described sampling prior to threshold operation when the input signal is limited and for selecting operation with normal sidelobe blanking comparison of compressed sidelobe signals when the input signal is at a level lower than the limiting amplitude of the channels.

High-sensitivity DPSK receiver for high-bandwidth free-space optical communication links

Abstract: A high-sensitivity modem and high-dynamic range optical automatic gain controller (OAGC) have been developed to provide maximum link margin and to overcome the dynamic nature of free-space optical links. A sensitivity of -48.9 dBm (10 photons per bit) at 10 Gbps was achieved employing a return-to-zero differential phase shift keying based modem and a commercial Reed-Solomon forward error correction system. Low-noise optical gain was provided by an OAGC with a noise figure of 4.1 dB (including system required input loses) and a dynamic range of greater than 60 dB.