A novel low-cost beam-steering technique based on the extended-resonance power-dividing method
A novel phased array based on the extended-resonance power-dividing method has been presented. This method eliminates the need for separate power splitter and phase shifters in a conventional phased-array system, resulting in a substantial reduction in circuit complexity and cost. As a proof of principle, a 2-GHz extended-resonance-based phased array using varactor diodes and microstrip patch antennas has been designed, fabricated, and tested. The measured scan range is 20/spl deg/ and the measured efficiency of the extended-resonance phased-array feed is typically 80%, which corresponds to 1 dB of insertion loss.
Voltage controlled ferroelectric lens phased arrays
Phased array antennas can steer transmitted and received signals without mechanically rotating the antenna. Each radiating element of a phased array is normally connected to a phase shifter, which determines the phase of the signal at each element to form a beam at the desired angle. The most commonly used phase shifters are ferrite and diode phase shifters. Phase shifters using ferroelectric materials have been proposed previously. A typical phased array may have several thousand elements and is very expensive. Therefore, reducing the cost and complexity of the phase shifters and the phase shifter controls is an important consideration in the design of phased arrays. The phased array described uniquely incorporates bulk phase shifting, the array does not contain individual phase shifting, using a ferroelectric material along with simpler phase shift control. Bulk phase shifting using diodes has been proposed and developed in the Radant lens. The lens described uses a voltage controlled ferroelectric, which introduces an analog phase shift rather than a digital phase shift as in the Radant lens. The ferroelectric lens has further advantages of smaller lens thickness, higher power handling, simpler beam steering controls, and it uses less power to control the phase shift compared to the Radant lens. Thus, it can potentially lead to low cost phased arrays.
Jet, Rocket, Nuclear, Ion and Electric Propulsion: Theory and Design
Jet, rocket, nuclear, ion, and electric propulsion; theory and design , Jet, rocket, nuclear, ion, and electric propulsion; theory and design , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی