Active antenna

About: Active antenna is a research topic. Over the lifetime, 2246 publications have been published within this topic receiving 26493 citations.

Noise analysis of an integrated travelling wave antenna

Abstract: A noise model for a developed active antenna is presented. The active antenna is a series of distributed of active devices and microstrip transmission lines. This poses an interesting problem in terms of noise analysis, because the active devices and antenna can no longer be separated. The developed noise model is verified with experimental measurements.

High accuracy position terminal based on big dipper ground reinforcing technique

Abstract: The utility model discloses a high accuracy position terminal based on big dipper ground reinforcing technique belongs to the satellite positioning technology field, including differential positioning module, GPRS module, singlechip, outside active antenna, GPRS antenna, SIM card module and a power module, adopt transmission of GPRS wireless network and meter level difference GNSS location finding technique, improved GPS positioner's precision, reduced GPS positioner's cost.

Transmit Antenna Selection and Beamformer Design for Secure Spatial Modulation with rough CSI of Eve

Abstract: The security of spatial modulation (SM) aided networks can always be improved by reducing the desired link's power at the cost of degrading its bit error ratio performance and assuming the power consumed to artificial noise (AN) projection (ANP). We formulate the joint optimization problem of maximizing the secrecy rate (Max-SR) over the transmit antenna selection and ANP in the context of secure SM-aided networks, which is mathematically a non-linear mixed integer programming problem. In order to solve this problem, we provide a pair of solutions, namely joint and separate solutions. Specifically, an accurate approximation of the SR is used for reducing the computational complexity, and the optimal AN covariance matrix (ANCM) is found by convex optimization for any given active antenna group (AAG). Then, given a large set of AAGs, simulated annealing mechanism is invoked for optimizing the choice of AAG, where the corresponding ANCM is recomputed by this optimization method as well when the AAG changes. To further reduce the complexity of the above-mentioned joint optimization, a low-complexity two-stage separate optimization method is also proposed. Furthermore, when the number of transmit antennas tends to infinity, the Max-SR problem becomes equivalent to that of maximizing the ratio of the desired user's signal-to-interference-plus-noise ratio to the eavesdropper's. Thus our original problem reduces to a fractional programming problem, hence a significant computational complexity reduction can be achieved for the optimization problem. Our simulation results show that the proposed algorithms outperform the existing leakage-based null-space projection scheme in terms of the SR performance attained, and drastically reduces the complexity at a slight SR performance reduction.

Method for controlling an active antenna

Abstract: A method for controlling an active antenna of individual transmitting/receiving elements, an optical beat signal being generated in the microwave frequency range by heterodyning two optical frequencies and, after electro-optical conversion, being applied with defined phase and amplitude to the individual transmitting/receiving elements of the antenna.

External antenna's big dipper hand holder in compatible

Abstract: The utility model provides an external antenna's big dipper hand holder in compatible belongs to the handheld quick -witted field of the big dipper, include: the built -in aerial, first low noise amplification and power amplification module with built -in antenna connection, multiplexer and the feed module be connected with first low noise amplification and power amplification module, the active antenna interface of being connected with multiplexer and feed module, the RNSS radiofrequency signal processing module who is connected with multiplexer and feed module, the RDSS radiofrequency signal processing module who is connected with multiplexer and feed module, the power amplifier drive feedback adjustment module of being connected with multiplexer and feed module and RDSS radiofrequency signal processing module respectively, the data processing module and the first power processing module that are connected with RNSS radiofrequency signal processing module and RDSS radiofrequency signal processing module respectively. It adds the active antenna interface in current big dipper hand holder, the realization is connected with external active antenna's to the application scene of the big dipper hand holder has been expanded.