This report describes recent progresses in development and production of GaN HEMT based power amplifiers in Wavice Inc., such as discrete transistors, s-band internally matched packaged transistors, 5W 3.5 GHz Doherty amplifiers, S-band Tx module and 4kW C-band high power amplifiers. Especially for s-band internally matched transistors and power amplifiers, more than 1500 products have been produced and qualified. The RF performance variations and reliability data from the qualification of power amplifiers are summarized.

In the dual-polarized radar system, the horizontally and vertically polarized signals can be exploited to improve the direction of arrival (DOA) estimation performance. In this paper, the DOA estimation problem is considered in the dual-polarized radar. By exploiting the target sparsity in the spatial domain, the sparse-based method is proposed after formulating the DOA estimation problem as a sparse reconstruction problem. In the traditionally sparse methods using the compressed sensing (CS) theory, the spatial domain is discretized into grids to establish a dictionary matrix and solve the sparse reconstruction problem, but the off-grid error is introduced in the discretized grids. Therefore, we formulate a novel definition of atomic norm for the dual-polarized signals and give an atomic norm-based method to denoise the received signals. Then, an efficient semidefinite program (SDP) is derived, and the DOA is estimated by searching the peak values of the denoised signals. Simulation results show that the proposed method can significantly improve the DOA estimation performance in the dual-polarized radar. Additionally, compared with the state-of-art methods, the proposed method has better estimation performance with relatively low computational complexity.