Yu Ji

Receive mode of optical signal processing multibeam array antennas

A receive mode of the optical processing array antennas is presented. In this receive mode, the transmitting radio frequency (RF) signals generated by optical processor will be shifted as local oscillator (LO) signals, and the received RF beams will be discriminated in the downconverted intermediate frequency (IF) frequency domain by a mixer array between the optical processor and antenna elements. A proof-of-concept experiment for a two-beam and four-element array antenna is demonstrated, and the received IF power distributions for each beam have very good agreement with the calculated antenna patterns.

High-Q whispering gallery mode dielectric resonator bandpass filter with microstrip line coupling and photonic bandgap mode-suppression

We describe a novel bandpass filter based on using whispering gallery (WG) modes in high-density dielectric resonators (DR). Microstrip line mode-coupling and photonic bandgap (PEG) suppression techniques are also features of this design. Based on this approach, we demonstrate a filter with center frequency of 13.7 GHz, Q of 2000, insertion loss of 7 dB, and attenuation of 30 dB.

Spatial optical processing array antenna for multibeam reception

We propose a multibeam receiving antenna using spatial optical processing technique in a beam forming network. Also we experimentally investigate the basic performance of optical-microwave conversion, a key technology for achieving this antenna.

A multibeam receiving array antenna by means of spatial optical signal processing

A multibeam receiving array antenna requires a beam-forming network (BFN) to separate signals according to the direction of signal arrival. When compared with conventional techniques which use a microwave BFN or the digital beam-forming array antenna, spatial optical signal processing has advantages with respect to the bandwidth, circuit complexity, size and weight. Spatial optical signal processing is a technique that uses optical spatial Fourier transform characteristics. ATR has proposed a beam shaping, beam scanning and multiple beam transmitting array antenna that uses spatial optical signal processing. In addition, we have proposed the concept of a receiving mode spatial optical signal processing array antenna. We show the configuration of our receiving mode spatial optical signal processing array antenna and also experimental results for the optical radiation patterns of a spatial optical signal processing BFN. The results for the radiation patterns are in good agreement with theoretically calculated values.

Beam formation by using optical signal processing techniques

We discuss the array antenna beam forming and multibeam operation controlled by an optical processor which performs signal processing by means of Fourier optics. We also give the antenna radiation pattern analysis, antenna system parameter evaluation, as well as a comparison with measured data.

Optical feed for multibeam microwave array antennas

A new optical feed for transmitting multibeam microwave array antennas is proposed by using spatial Fourier optical processing. The system design is given with consideration of generating overlapping multiple beams. A two-beam experimental optical feed is demonstrated. Two RF signals of 800 MHz and 1 GHz with different phase distributions for feeding to array antennas are obtained and measured spatially.