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A novel detection for stealthy target model F-117A with a higher aspect vision is introduced by using Stratospheric Balloon-borne Bistatic radar system. The potential problem of proposed scheme is platform instability impacted on the balloon by external wind force. The flight control system is studied in detail under typical random process, which is defined by Dryden turbulence Spectrum. To accurately detect the stealthy target model, a real Radar Cross Section (RCS) based on physical optics (PO) formulation is applied. The detection of proposed scheme has been improved due to increasing PO-scattering field of stealthy model with higher aspect angle comparing to the conventional Ground-based system. Simulations demonstrate that proposed scheme gives much higher location accuracy and reduces location errors.

In order to meet the application requirements of radar networks for high efficiency and high second harmonic suppression (SHS) of power amplifiers, this paper proposes a C-band 30 W power amplifier (PA) microwave monolithic integrated circuit (MMIC) based on 0.25 μm gallium nitride (GaN) high electron mobility transistor (HEMT) process. The proposed PA uses a two-stage amplifier structure to achieve high power gain. A topology with SHS is designed in the output-matching network. Besides, the large signal model load pull simulation and the harmonic control technology in the output stage are used to improve efficiency. The high-power additional efficiency (PAE) and high SHS of the PA MMIC are achieved simultaneously. In the 5–6 GHz frequency range, multiple indicator measurements of the proposed PA show that output power is over 45 dBm, the PAE is more than 57%, the SHS exceeds 45 dBc, the power gain is greater than 24 dB, which are conducted under the condition of 100 μs pulse width and 10% duty cycle. In addition, the size of the PA MMIC, including bonding pads, is 3.3 × 3.1 mm2.

This paper introduces a miniaturized system in package (SIP) for a Ku-band four-channel RF transceiver front-end. The SIP adopts the packaging scheme of an inner heat-dissipation gasket and multi-layer substrate in the high temperature co-fired ceramics (HTCC) shell with a metal heat sink at the bottom. The gasket effectively solves the heat-dissipation problem of high-power transceiver chips, and the multi-layer substrate achieves the interconnection between multiple chips. Within the limited size of 14.0 × 14.0 × 2.5 mm3, the SIP integrates five bidirectional amplifier chips, an amplitude-phase control multi-function chip, and two power modulation chips to realize the Ku-band four-channel RF transceiver front-end. Transmitting power over 0.5 W (27dBm) and receiving noise figure of 3.4 dB are achieved in the Ku-band. The efficient heat dissipation, high air tightness, and excellent integration are simultaneously realized in this SIP. The measurement results show that the performance is stable in the receiving and transmitting states, and the SIP based on HTCC technology has specific prospects for radar transceiver application.

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