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Yoshinori NAKASUGA Kohji HORIKAWA Hiroyo OGAWA
A new configuration is proposed for an optoelectronic network (OEN) using microwave frequency mixing and multiplexing. The mn OEN consists of m optical sources, m-parallel n-stage cascaded optical intensity modulators, and m-photodetectors. The mn OEN matrix is theoretically discussed, and 12, 22 and 33 OENs are analyzed in detail. The 22 OEN, which mixes and multiplexes microwaves, is further investigated and the theoretical prediction derived from OEN equations is experimentally confirmed.
Kohji HORIKAWA Ikuo OGAWA Tsutomu KITOH Hiroyo OGAWA
This paper proposes a photonic integrated beam forming and steering network (BFN) that uses switched true-time-delay (TTD) silica-based waveguide circuits for phased array antennas. The TTD-BFN has thermooptic switches and variable time delay lines. This TTD-BFN controls four array elements, and can form and steer a beam. An RF test was carried out in the 2.5 GHz microwave frequency range. The experimental results show a peak-to-peak phase error of 6.0 degrees and peak-to-peak amplitude error of 2.0 dB. Array factors obtained from the measured results agree well with the designed ones. This silica-based beam former will be a key element in phased array antennas.
Takana KAHO Hiroshi OKAZAKI Tadao NAKAGAWA Katsuhiko ARAKI Kohji HORIKAWA
An S-band linearizer was developed using GaAs MMIC technology. We call it the even-order-distortion-implemented intermodulation distortion controller (EODIC). EODIC uses even-order intermodulation distortion (IM) components in the second harmonic frequency band to control its IM components in the fundamental frequency band. EODIC is a suitable tool to compensate near-saturated high power amplifiers (HPAs). We developed an EODIC using MMIC technology. This paper describes the principle of EODIC and then introduces the EODIC MMIC in detail. This paper also presents the IM reduction performance of an EODIC in a near-saturated HPA.