This paper describes the outline of recent standardization activities for Radio on Fiber (RoF) transmitter by IEC TC103/WG5. RoF transmitter consists of optical fibers, electrical to optical (E/O) converter, and optical to electrical (O/E) converter. IEC TC103/WG5 is working on standardization on measurement method of E/O and O/E devices, and technical specification of RoF transmitter. This paper overviews those standardization activities which are being developed by TC103/WG5 as well as the National Committee of WG5.

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.

The performance of a traveling wave Mach-Zehnder external optical modulator (EOM) mixer is described and compared with a conventional diode mixer's performance. Additionally, by incorporating external circuitry, the EOM mixer can provide single sideband suppression in addition to the inherent local oscillator suppression. The basic frequency mixing function of the EOM mixer is first described theoretically and then extended to the sideband suppression case. The performance of both configurations is also presented. Achievable electrical isolation between LO (carrier) and RF (upconverted data signal at LOIF) frequencies is greater than 95 dB and total link conversion loss is 37 dB in this demonstration with a laser diode source. Sideband suppression of greater than 43 dB with respect to the desired sideband at the photodetector output is achieved.

This paper proposes an MMIC image rejection mixer and an MMIC balanced mixer employing multilayer microstrip lines and high-electron-mobility-field-effect-transistor (HEMT)s with a LUFET configuration (line-unified HEMT module). The advantage of the mixers is remarkable chip size reduction by the combination of the two technologies. The multilayer microstrip line, in which one microstrip line is placed upon another, is used for stacking passive circuits, e.g. a 90 hybrid and distributed lines, to reduce the chip-area occupied by transmission lines, and to allow flexible line allocation. The line-unified HEMT module provides all functions required for in-phase/out-of-phase power divider/combiners in HEMT electrode and unified coplanar lines configuration. A 29-32 GHz image rejection mixer and a 3-27 GHz balanced mixer are realized in only 1.6 mm 1.0 mm and 1.8 mm 1.2 mm MMIC chip size, respectively.

The design and performance of a millimeter-wave video transmission system using 60-GHz band for indoor broadcasting-satellite (BS) signals transmission is presented. This system can transmit multiple video signals such as broadcasting signals and user-oriented signals to a television set indoors. To minimize the local oscillator's frequency offset and phase-noise effects, the system uses a remote-heterodyne scheme. Based on the concept, the system is developed to meet required carrier-to-noise-power-ratio (CNR) and 3rd-order intermodulation (IM). The BS transmission was experimentally done by using the transmitter and receiver setup. The results are very promising and show the feasibility of the system.

We experimentally demonstrated a remote antenna system based on a millimeter-wave (MMW) over fiber scheme for 622-Mbps broadband fixed wireless access systems. In this system, the format of the RF signal is based on a four-carrier signal in which each carrier is modulated by using 64-QAM, to reduce the complexity of the RF system in comparison with the single-carrier QAM system using many more signal-points than 64. The remote antenna system based on the IF-over-fiber scheme was also experimentally demonstrated, as well as the MMW over fiber scheme for comparison. From the experimental results, we found that the remote antenna system based on the MMW over fiber scheme is effective not only from the viewpoints of miniaturization of the remote antenna station and ability to provide a stable millimeter-wave frequency, but also from the viewpoint of link performances such as allowable dynamic range and power penalty, even though the scheme's E/O and O/E devices have a higher cost.

The onboard antenna beam forming network (BFN) of the next-generation communication satellites must offer multiple beam forming and beam steering. The conventional BFN, which directly controls the array elements, is not suitable for a large-scale array antenna because of the difficulty of BFN control. This paper proposes a new BFN configuration that consists of three/four-way variable power dividers and a Butler matrix (FFT circuit). This BFN can offer continuous beam steering with fewer variable components. By introducing new techniques based upon excluding FFT periods and power evaluations by definite integration, the deviation in beamwidth is reduced by 75% or more and the maximum sidelobe level is improved by 10 dB or more.

A new automatic-threshold-control (ATC) system for the amplitude-shift-keying (ASK) transceivers without using automatic gain control (AGC) was developed. When signal-to-noise ratio (SNR) in a transmission system fluctuates, the new system optimizes the threshold by statistic processing. In this paper, the schematic block diagram, the theory of statistical processing, and the performance estimated by numerical simulations are shown. The simulations show that under ideal conditions, the system can control the threshold voltage in a broad SNR region (wider than 20 dB). Delay of response and trapping in real situation can occur, but, the problems can be avoided by waveform shaping. It is thus concluded that the new ATC system can be applied to ASK transceivers.

A fiber-optic broadband signal distribution link based on a millimeter-wave self-heterodyne transmission/optical remote heterodyne detection technique was developed. To avoid having to use expensive optical and millimeter-wave devices to construct a frequency-stable fiber-optic millimeter-signal transmission system, a millimeter-wave self-heterodyne transmission technique was used, in which transmitted signals were generated by an optical remote heterodyne detection scheme. Theoretical discussion and experiments demonstrated that it is possible to construct an inexpensive millimeter-wave signal distribution link without the complexity or difficulties of a conventional link structure because applying the principle of the millimeter-wave self-heterodyne transmission technique enables the use of an unstable millimeter-wave carrier generated by heterodyning of two independently operating lasers. It was experimentally demonstrated that the proposed fiber-optic millimeter-wave link could successfully achieve bit-error-free transmission of a 156-Mb/s QPSK-formatted signal over a 10-km fiber link and a 5-m pseudo-air link.

This paper proposes three configurations of slow-wave transmission lines for MMICs, i.e., double crosstie slow-wave transmission line (DCT-SLW), meander-like DCT-SLW and lumped DCT-SLW. The DCT-SLW is based on periodic structures and triplate structures. The meander-like DCT-SLW realizes a drastic size reduction in the DCT-SLW using a meander configuration of inductive and capacitive transmission lines. The multilayer spiral inductors are introduced to obtain high impedance characteristics of the meander section. The lumped DCT-SLW achieves a large slow-wave factor of 30. These proposed structures are analytically and experimentally investigated, and excellent performance is obtained. It is also shown that the proposed DCT-SLWs are superior to thin film microstrip (TFMS) lines with the same insertion phase, as regards size.