An adaptive impedance matching system for mobile communication antennas

Abstract

AbsfroctAn adaptive impedance matching sysrcrn is proposed. This system employs only a simple algonfhm for E D~V S T~~~E C , therefore docs not need any c~mpli~sled mathematical formulation for modeling o f the system itself as well as its nodincar ~onfrol elements. Also the proposed system utilizcs only simple digital circuits for timing generation and basic analog cireuitr. Even with a small range of capacimcc for c " l Clement in B matching Circuit. the improvement in the mim"h is obisrvcd by 2-3dB over an impedance matching circuit wilh fixed capacitances.

Performance Evaluation for RF-Combining Diversity Antenna Configured with Variable Capacitors

“…In this paper, we focus on how fast convergence can be achieved and do not emphasize whether the solution gives a global maximum or local. Here, the perturbation method [9] and steepest gradient method [10] are considered for the optimization algorithms. The output SNR Γ(x) is used as the cost function where x is the reactance vector of variable capacitors.…”

IMPEDANCE MATCHING CONTROLLER FOR AN INDUCTIVELY COUPLED PLASMA CHAMBER - L-type Matching Network Automatic Controller

“…The automatic impedance matching problem has been solved using neural networks (Vai and Prasad, 1993), genetic algorithms (Thompson and Fidler, 2000) (Sun and J.K., 1997) (Sun and J.K., 1999), deterministic tuning algorithms with look-up tables (Moritz and Sun, 2001) and using adaptive systems (Parro and Pait, 2003) (Ida et al, 2004c) (Ida et al, 2004a) (De Mingo et al, 2004 (Ida et al, 2004b); nonlinear control systems have been also considered (Cottee, 2003). In all of the above mentioned cases, the load impedance is not affected by the matching conditions while, in the case studied (inductively coupled plasma discharges), the load impedance is varying during the matching process.…”