A 60-GHz point-to-multipoint millimeter-wave fiber-radio communication system

A 60-GHz point-to-multipoint wireless access link with data rate of 156 Mb/s incorporating 60-GHz transceiver modules and full-duplex fiber-optic millimeter-wave transmission is developed for short-range applications such as indoor wireless local area networks and intelligent transport systems. For compact system configuration, a small-size millimeter-wave transceiver module with planar antennas is developed. The transceiver module is based on broadband planar integration and packaging of millimeter-wave circuits. The RF output power is +10 dBm and the measured 3-dB antenna beamwidth is 30/spl deg/. The total size of the developed 60-GHz transceiver module, except input and output connectors, is 50 mm /spl times/ 75 mm /spl times/ 35 mm. A point-to-point full duplex fiber-optic configuration is extended to the scheme with multiple access points (APs) by using a tree coupler and a dense wavelength division multiplexing multiplexer. The AP has a simple configuration without frequency conversion. The bit error rate and packet error rate performances of the 60-GHz fiber-radio access link are evaluated. Furthermore, the effect of the extension to the scheme with multiple APs is investigated.     

Long-term stabilized millimeter-wave generation using a high-powermode-locked laser diode module

In this paper, a 60-GHz-band millimeter-wave (mm-wave) signal generation using a new 60-GHz mode-locked laser diode (MLLD) module stabilized by an optical injection will be presented. To modularize the MLLD, the precise position alignments and the fine tuning for the repetition rate is released; moreover, the output optical power of more than 6.0 dBm and the stability over nearly 1500 h are obtained. It is experimentally confirmed that the frequency and power stabilities are several tens of hertz and less than 1 dBm, respectively. The generated 60-GHz-band mm-wave signal with the 3-dB linewidth of less than 300 Hz over a 100-km-long optical fiber link is also successfully demonstrated     

120-GHz-band millimeter-wave photonic wireless link for 10-Gb/s data transmission

A 120-GHz-band wireless link that uses millimeter-wave (MMW) photonic techniques was developed. The output power and noise characteristics of 120-GHz-band MMWs generated by converting a 125-GHz optical subcarrier signal were evaluated. It was then shown that the noise characteristics of the 125-GHz signal generated with these photonic technologies is sufficient for 10-Gb/s data transmission. We constructed a compact 120-GHz-band wireless link system, and evaluated its data transmission characteristics. This system achieved error-free transmission of OC-192 and 10-GbE signals over a distance of more than 200 m with a received power of below -30 dBm.     

An LTCC-Based Wireless Transceiver for Radio-Over-Fiber Applications

This paper describes the realization of a low-temperature co-fired ceramic (LTCC)-based wireless transceiver with optical interface for radio-over-fiber applications involving several standards. The RF front-end including an antenna is fabricated in LTCC technology, while the optical transceiver with a single-mode optical interface is built on a silicon motherboard. The front-end operates in the 5-6-GHz band, while the modulated optical carrier is transmitted at 1.55-mum wavelength. The front-end module is an attractive solution for wireless local area network applications such as IEEE 802.11a or HIPERLAN2 requiring a direct link to an optical backbone     

Loop-Back Optical Heterodyne Technique for 1.0-Gb/s Data Transmission Over 60-GHz Radio-On-Fiber Uplink

An optical-heterodyne-detection method for a 60-GHz radio-on-fiber uplink is proposed and verified in this paper. The main point of this proposal is that all the functions needed for the optical heterodyne detection, i.e., the local/carrier light sources, the automatic frequency control of these light sources, and a polarization-diversity-detection circuit, are consolidated in one transmitting-side module to realize a simple system configuration. This proposal realizes an adequate optical uplink budget with low-cost optical receivers that consist of just one IF-band photodetector and one envelope detector. A 1.0-Gb/s transmission experiment over 10 km of single-mode fiber, which represents access-network transmission, is demonstrated using a 61.0-GHz amplitude-shift-keying signal as a 60 GHz-band uplink signal. A BER of less than 10-9 was obtained at an uplink SSB signal power of -40 dBm regardless of the polarization state of the optical uplink signal, and no significant dispersion-induced degradation was noted.     

A 60-GHz-Band Analog Optical System-on-Package Transmitter for Fiber-Radio Communications

We developed an analog optical system-on-package (SoP) transmitter for a 60-GHz-band radio-over-fiber (RoF) link. The SoP transmitter consisted of an electroabsorption modulator, radio frequency amplifiers, and a bandpass filter. The 60-GHz RoF wireless link was prepared to measure the performance of the SoP transmitter. The transmission characteristics of 64-quadrature amplitude modulation (64-QAM) data of the 60-GHz RoF wireless link, including the SoP transmitter, were investigated by measuring the error vector magnitude (EVM) and signal-to-noise ratio (SNR) with a baseband frequency. The EVM of the 60-GHz RoF wireless link was between 2.25% and 2.80%, and the SNR was between 27.36 and 29.31 dB from 140 and 770 MHz, at input baseband power of -9 dBm. The noise figure had the minimum of 8.44 dB at 500 MHz. We successfully transmitted digital community antenna television (CATV) system signals through the 60-GHz RoF wireless link, including the SoP transmitter. Digital CATV signals of 86 channels could be transmitted through the 60-GHz RoF wireless link, and the total throughput was found to be 2.61 Gb/s.     

A 2.2-V operation, 2.4-GHz single-chip GaAs MMIC transceiver forwireless applications

A 2.2-V operation, single-chip GaAs MMIC transceiver has been successfully developed for 2.4-GHz-band wireless applications such as wireless local area network terminals. The chip is fabricated using a planar self-aligned gate field-effect transistor. To generate sufficient negative voltage for gate-biasing and to enhance switch power handling capability under a 2.2-V supply, a newly designed negative voltage generator with a voltage doubler (NVG-VD) and a switch control logic circuit are integrated on the chip, together with a power amplifier, a transmit/receive switch, and a low-noise amplifier. The NVG-VD is designed to produce both a 3.3-V positive step-up voltage and a -2.1-V negative voltage under 2.2 V in operation voltage. Biased with these outputs, the logic circuit accommodates high power outputs of over 25 dBm with a low operating voltage of 2.2 V in transmit mode, With a 2.45-GHz modulated signal based on IS-95 standards, a 21-dBm output power and a 33% efficiency are obtained at a ±1.25-MHz-offset adjacent channel power rejection of -45 dBc. In receive mode, a low-noise amplifier achieves a 1.8-dB noise figure and an 11-dB gain with a 3.0-mA current. This transceiver enables significant size and weight reductions in 2.4-GHz-band wireless application terminals     

A 50 GHz GaAs FET MIC transmitter/receiver using hermetic miniatureprobe transitions

A very compact 50-GHz-band transmitter/receiver for a video link is described. The RF assemblies used in the system consist of 25/50-GHz frequency doublers, a 25-GHz dielectric-resonator oscillator, and a 25-GHz FM modulator. The circuits make extensive use of microwave integrated circuit (MIC) technology with all GaAs FETs as active elements. The frequency doublers exhibit a minimum conversion loss of 2.6 dB and a maximum output power of 11 dBm. The modulator is highly frequency stabilized by the dielectric resonator. Recently developed miniature probe microstrip-to-waveguide transitions permit the MIC assemblies to be installed compactly in hermetically sealed packages. Design considerations and experimental data for the transition are presented. Using these technologies a transmitting power of 10 dBm and a receiver noise figure of 13 dB have been obtained     

多通道高速数字收发设计

雷达系统小型化的发展趋势要求收发分系统不断提高集成度以减小设备体积。文中介绍了一种多通道高速数字收发模块的设计方法,在一个模块上同时实现16通道射频波形产生和16通道中频采集功能。波形产生基于数字直接合成方式,工作频率1.6 GHz,可直接输出射频波形,波形控制参数可通过光纤接口调节。中频采样使用多通道模数转换器芯片实现,阻抗匹配电路保证了模数转换的性能。测试表明:模块性能指标满足系统使用需求,且已成功应用于某雷达系统中。     

Full-Duplex 60-GHz RoF System With Optical Local Oscillating Carrier Distribution Scheme Based on FWM Effect in SOA

A full-duplex 60-GHz radio-over-fiber (RoF) system using novel optical local oscillating (LO) carrier distribution scheme to reduce the system cost and realize centralized management is proposed and experimentally demonstrated. In the proposed scheme, the optical LO carriers for producing remote electrical LO signals at the base stations (BSs) are generated together with the downlink RoF carriers at the central station (CS) via four-wave-mixing effect in semiconductor optical amplifier, and are then distributed to the BSs along with the downlink RoF signals. By down-converting the 60-GHz-band uplink signal with the remotely produced 60-GHz LO signal and reusing the optical LO carriers as the uplink optical source, only a cost-effective intermediate frequency modulator is required at each BS to transmit the uplink signal, which will dramatically reduce the whole system budget due to a large amount of BSs. Moreover, the operating frequency of each BS can be controlled remotely at the CS end to realize centralized management and convenient reconfiguration. Using the proposed scheme, 622-Mb/s signals for both directions are successfully transmitted over a 20-km single-mode fiber link and a 50-cm wireless channel with less than 0.1- and 0.2-dB power penalty for downlink and uplink, respectively.      

Design and Development of Advanced Cavity-Based Dual-Mode Filters Using Low-Temperature Co-Fired Ceramic Technology for V-Band Gigabit Wireless Systems

In this paper, a novel concept of 3-D integrated -band dual-mode cavity filters, which permit the realization of a variety of quasi-elliptic responses by creating transmission zeros, has been demonstrated using multilayer low-temperature co-fired ceramic (LTCC) technology. A single-cavity resonator is designed to generate a degenerate resonance of two orthogonal modes ( and ), enabling dual-mode operation. The appearance and elimination of transmission zeros have been analyzed through the multipath coupling diagrams and lumped-element models. The quasi-elliptic dual-mode filters with the appropriate locations of the transmission zeros are then developed for receiver and transmitter channels of a -band transceiver module. Two pre-synthesized, dual-mode cavity filters are vertically stacked with two types of inter-coupling slots (1: rectangular, 2: cross) to realize the multipole filters for 60-GHz wireless local area network narrowband applications. These proposed filters are the first to be reported and have great potential to be integrated into miniaturized -band LTCC transceiver modules.     

60-GHz System-on-Packaging Transmitter for Radio-Over-Fiber Applications

Using ultra-high-speed electroabsorption modulator (EAM) devices for RF/optic conversion, we fabricated system-on-packaging (SOP) transmitter (Tx) modules and characterized their performance in 60-GHz RF/radio-over-fiber (ROF) applications. Both an EAM and low-noise amplifiers (LNAs) were co-packaged with internal bias circuits into a butterfly-type metal housing. At the EAM temperature, $T {sim} {hbox{25}}~^{circ}$ C and the EAM reverse bias, $V_{R} {sim} $1.6 V was the largest RF gain obtained that was very susceptible to the change of $T$ . The impedance matching in the 60-GHz band was accomplished with both a microstrip-line bandpass filter and a 500- $Omega$ shunt resistor, which defined the 2-GHz passband of the SOP transmitter. In 60-GHz two-tone experiments, we observed that the spurious free dynamic range of an SOP module with two LNAs was 78 dB $cdot$ Hz $^{2/3}$ while that of the narrowband EAM module showed 82 dB $cdot$ Hz$^{2/3}$. In contrast, the noise figure exhibited a large reduction of up to 30 dB for the SOP module compared with the narrowband EAM module. Using the SOP Tx module, we achieved successful transmission of commercial high-definition digital CATV signals in 64-quadrature amplitude modulation (QAM) format through the 60-GHz RF/ROF link. The total throughput of the link was estimated to be 6.5 Gb/s.      

Simultaneous Transmission of Wireless and Wireline Services Using a Single 60-GHz Radio-Over-Fiber Channel by Coherent Subcarrier Modulation

We proposed and experimentally demonstrated a novel hybrid subcarrier modulation (H-SCM) technique to generate a spectral-efficient 60-GHz optical millimeter-wave (mm-wave) that carries independent 2.5-Gb/s wireless and 10-Gb/s wireline signals using intensity and phase modulation, respectively. The frequency beating components of the 60-GHz channel due to interleaved and imbalanced optical path in H-SCM are numerically analyzed and experimentally measured in terms of timing jitter and amplitude fluctuation. The generated 60-GHz optical mm-wave signal using H-SCM with phase noise variance of about 0.5 is demonstrated in a radio-over-fiber testbed propagating through a combined distance of 25-km fiber and 4-m free space. The power penalties for the received wireless and wireline signals are 1 and 0.2 dB at $10^{-9}$ bit-error rate, respectively.      

A single-chip GaAs RF transceiver for 1.9-GHz digital mobilecommunication systems

A 1.9-GHz single-chip GaAs RF transceiver has been successfully developed using a planar self-aligned gate FET suitable for low-cost and high-volume production. This IC includes a negative voltage generator for 3-V single voltage operation and a control logic circuit to control transmit and receive functions, together with RF front-end analog circuits-a power amplifier, an SPDT switch, two attenuators for transmit and receive modes, and a low-noise amplifier. The IC can deliver 22-dBm output power at 30% efficiency with 3-V single power supply, The new negative voltage generator operates with charge time of less than 200 ns, producing a low level of spurious outputs below -70 dBc through the power amplifier. The generator also suppresses gate-bias voltage deviations to within 0.05 V even when gate current of -144 μA flows. The IC incorporates a new interface circuit between the logic circuit and the switch which enables it to handle power outputs over 24 dBm with only an operating voltage of 3 V. This transceiver will be expected to enable size reductions in telephones for 1.9-GHz digital mobile communication systems     

Dense wavelength-division multiplexing millimeter-wave-band radio-on-fiber signal transmission with photonic downconversion

Photonic downconversion (PDC) technique for dense wavelength division multiplexing (DWDM) millimeter-wave-band radio-on-fiber (ROF) uplink systems is investigated. The PDC technique is carried out for a lump of all uplink wavelength division multiplexing (WDM) ROF signals at a central station. Each channel is optically separated, photodetected, and demodulated individually without serious signal degradation due to the fiber dispersion effect. Error-free 25-GHz-spaced DWDM transmission and demultiplexing of two 60-GHz-band, 155-Mb/s differential phase-shift keying (DPSK) ROF signals over 25-km-long standard single-mode fiber (SMF) are experimentally demonstrated.     

A WiMedia/MBOA-Compliant CMOS RF Transceiver for UWB

A WiMedia/MBOA compliant RF transceiver for ultra-wideband data communication in the 3-5-GHz band is presented. The transceiver includes receiver, transmitter and synthesizer is completely integrated in 0.13-mum standard CMOS technology. The receiver uses a feedback-based low-noise amplifier (LNA) to obtain an RF gain of 4 to 37 dB and an overall measured noise figure of 3.6 to 4.1 dB over the 3-5-GHz band of interest. The transmitter supports an error vector magnitude (EVM) of -28 dB up to -4 dBm output power and meets the FCC and WiMedia mask specifications. The power consumption from a single supply voltage of 1.5 V is 237 mW for the receiver and 284 mW for the transmitter, both including the synthesizer     

Chip-package codesign of a low-power 5-GHz RF front end

Future high-performance wireless communication applications such as wireless local area networks (WLANs) around 5 GHz require low-power and highly integrated transceiver solutions. The integration of the RF front end especially poses a great challenge in these applications, as traditional front-end implementations require a large number of external passive components. In this paper, we present the single-package integration of complete transceivers based on a thin-film multichip module (MCM) technology with integrated passives. The MCM substrate is a a common carrier onto which different ICs are mounted. passive components such as RF bandpass filters, inductors, capacitors, and resistors are directly integrated into the MCM substrate with the use of the multilayer structure of the MCM technology. The “system-on-a-package” approach is illustrated with a voltage-controlled oscillator for Digital European Cordless Telephone (DECT) applications and a 5-GHz WLAN front end. These examples indicate that this approach yields a compact low-power implementation of complete transceivers for high-performance wireless applications     

Single mode fiber MT-RJ SFF transceiver module using opticalsubassembly with a new shielded silicon optical bench

Demand for a compact cost reduced optical transceiver has arisen. Small form factor (SFF) optical transceivers are expected to meet this demand. A new concept optical module based on V-grooved silicon optical bench (SiOB) technology, that enables a passive alignment of optical fibers and optical devices is expected to reduce the cost. MT-RJ SFF optical transceivers require this new packaging technique because the distance between input and output optical axes is shorter than conventional transceivers. However, crosstalk between a transmitter and a receiver is a big issue to be solved because the distance between optical axes of the laser diode (LD) and the photo diode (PD) is only 0.75 mm. It is difficult to reduce the crosstalk in a SiOB because large electromagnetic coupling exists due to the conductivity of a silicon substrate. A newly developed, low crosstalk optical subassembly (OSA) with a single mode fiber MT-RJ receptacle and the SFF transceiver module are reported. We have analyzed a mechanism of electrical crosstalk in a SiOB and developed a shield structure to reduce it. The crosstalk in the OSA with shielded SiOB was reduced over 20 dB compared to the unshielded SiOB     

Demultiplexing using an arrayed-waveguide grating for frequency-interleaved DWDM millimeter-wave radio-on-fiber systems

The frequency-interleaved dense- wavelength-division-multiplexing (DWDM) millimeter-wave (mm-wave) radio-on-fiber is an indispensable technique to improve the optical spectrum efficiency. We propose possible configurations of multiplexing and demultiplexing (DEMUX) schemes using an arrayed-waveguide grating (AWG) with two input and N output waveguides (N: total channel number). In this paper, we focus on the DEMUX scheme and experimentally demonstrate the DEMUX scheme using a commercially available AWG. In the experiment, 25-GHz-separated two-channel optical double sideband signals modulated by a 60-GHz millimeter-wave carrying a 156-Mb/s data are optically multiplexed by the frequency interleaving. The power penalty after DEMUX, which was due to interchannel interference, was less than 0.5 dB. We also made a transmission experiment over 25-km standard single-mode fiber (SMF). No noticeable power penalty in the received data due to chromatic dispersion of the transmission fiber was observed. This is because only the carrier and a sideband are detected in the proposed DEMUX scheme.     

A compact coaxial-type optical transceiver module using ahalf-transmittance photodiode for TCM optical access networks

A compact coaxial-type optical transceiver module has been developed without using a conventional 3 dB optical coupler. This transceiver is composed of a newly designed half-transmittance photodiode (HT-PD) and a 1.3-μm-MQW-LD. An HT-PD is used both as a photodetector and as a window for LD light. Fiber output power of 1.15 mW at the drive current of 26 mA and responsivity of 0.48 A/W at the reverse-voltage of 5 V were obtained. Temperature dependence of responsivity is also reported