This paper proposes radio frequency (RF) source Localization in a non-line of sight condition using the map of obstacles. Received signal strength indicator (RSSI) and angle of arrival (AOA) measurements are observations obtained from the signal received on the unmanned aerial vehicles (UAV). In the proposed approach, AOA is used to determine the obstacle on the map from which the reflection has happened. Then, RSSI information is used to determine the location of the RF source. In the basic version of the approach, the RF source is located by triangulation. In the advanced approach, the reflection angle is also estimated to improve the Localization accuracy. The estimation is done using the particle filter approach. In addition, it is shown analytically that the maximum Localization error for the advanced approach is bounded, but the relative formation of the reflectors with respect to each other can increase the Localization error for the basic approach.

This study uses an obstacle map for three-dimensional radio frequency (RF) source Localization with reflection. The received signal strength indicator (RSSI) and the angle of arrival (AOA) are the observation requirements for the three-dimensional Localization. In the first step of the Localization, an unmanned aerial vehicle (UAV) is used to obtain AOA and locate the three-dimensional reflection using a two-dimensional map. Then, the path loss function is used and the reflection angle alongside the distance between the receiver and RF source is estimated based on RSSI. This information is integrated with the information from the two-dimensional map to estimate the RF source location in the three-dimensional space. The possible RF source locations in three-dimensional space are obtained, and it is shown that the possible locations of the RF source for one reflection in the three-dimensional make a circle, so three reflections are required for three-dimensional RF source Localization. An improved particle filter is used to estimate RF source location while using the Kullback-Leibler distance (KLD) criteria and local search to improve the method performance with proper estimation speed and accuracy. The simulation results show that the improved particle filter has an adequate estimation with optimal particle number and higher execution speed than the initial particle filter.

In this paper, a new algorithm based on ESPRIT is proposed for the estimation of central angle and angular extension of Incoherently Distributed (ID) sources. The central angles are estimated using TLS-ESPRIT. The covariance matrix is approximated using a finite Taylor series expansion which leads to the formulation of covariance matrix in terms of central moments of the angular power distribution. The extension widths are estimated using the central moments of distribution. The algorithm can be used for sources with different angular distributions and has low computational cost.

Microwave coupling plays an important role to energize the electrons in an electron cyclotron resonance ion source (ECRIS) plasma. Several components are hired for wave transition from a magnetron to the ECR plasma chamber. In this work, DC break, pressure window, ridged waveguide and plasma chamber have been designed and simulated by COMSOL Multiphysics to transmit the microwave power. The power and frequency are 1 kW and 2.45 GHz, respectively. The results show the TE111 mode gets excited and 9.9 mm quartz pressure window maximize the forward transmission power to the cavity. The DC break is based on utilizing the insulating rings along the WR-284 waveguide, which has low wave return loss for a wide range of frequencies. A four-ridged waveguide is considered for impedance matching and electric field focusing. The amplification of the electric field in the middle of cylindrical plasma chamber is satisfied with dimensions of Ø9 cm×10 cm.

A high-power solid-sate based radio frequency power source is introduced in this paper. Solid-state based amplifiers are much more efficient than microwave tubes and can be used in compact electron cyclotron resonance (ECR) ion sources. A reliable negative bias voltage controller is proposed to drive the power source’, s main power amplifier, which can deliver up to 300 W power to the ion chamber. The selected high-power transistor is internally matched on the input side but the output side is matched in this paper to deliver maximum power to the load. The bias circuit was fabricated on an FR4 substrate and measurement results were obtained to verify the functionality of the bias sequencer. Analog simulations were done by LTSPICE and high-frequency simulations are performed with the momentum RF simulator of Advanced Design System (ADS). The output power of the proposed structure is tunable with 0. 5 dB resolution and can deliver 300 mW to 300 W power to the ion chamber.