In this paper, an automatic identification method based on frequency discrimination is proposed. The proposed method can be used when the received signal is a constant envelope modulation scheme. To test the proposed method PSK and FSK are considered. Using computer simulations, the performance of the proposed method was evaluated and found to be able to distinguish between PSK and FSK well even in the presence of noise.

This paper presents a new open-loop phase shifter and frequency synthesizer which can be implemented by small hardware. In the proposed method the differential square wave is converted to a differential ramp. Then the cross points of two ramps are detected as the middle points of high or low durations and are recovered to full digital levels, for 90shifting operation. 4-phases in 50 MHz frequency can be generated by 3.5 mW power consumption and 60 µm60 µm area. All circuits have been simulated in 0.35 µm CMOS technology.

Application of microwave and millimeter-wave circuit technologies to InGaP-HBT ICs for 40-Gbps optical-transmission systems is demonstrated from two aspects. First, ICs for various important functions -- amplification of data signals, amplification, frequency doubling, and phase control of clock signals -- are successfully developed based on microwave and millimeter-wave circuit configurations mainly composed of distributed elements. A distributed amplifier exhibits ≥164-GHz gain-bandwidth product with low power consumption (PC) of 71.2 mW. A 20/40-GHz-band frequency doubler achieves wideband performance (40%) with low PC (26 mW) by integrating a high-pass filter and a buffer amplifier (as a low-pass filter). A compact 40-GHz analog phase shifter, 20- and 40-GHz-band clock amplifiers with low PC are also realized. Second, a familiar concept in microwave-circuit design is applied to a high-speed digital circuit. A new approach -- inserting impedance-transformer circuits -- to enable 'impedance matching' in digital ICs is successfully applied to a 40-Gbps decision circuit to prevent unwanted gain peaking and jitter increase caused by transmission lines without sacrificing chip size.

All optical analog-to-digital converter consisting of an optical polarization modulator using nonlinear phase shift and switches based on polarization is proposed. The principle of operation is discussed using Jones matrix. Optical polarization states through the system and limit of resolution are evaluated. The resolution is optimized by maintaining the polarization state in the converter and refining the polarization of incident sampling signal. Parallel usage of converter modules is proposed to increase the dynamic range, where cyclic nature of optical phase plays an important roll. Application to photonic routing of our converter is also proposed.

Optical processing with efficient coding is expected in photonic label routing network. We consider optical codes encoded in the time and spectral domains. Wavelength-selective devices are useful for effective processing of such optical codes. In this study, collinear acoustooptic (AO) switches are investigated as a constituent elements of a wavelength selective correlator for optical BPSK codes. It is theoretically shown that the number of optical codes that can be distinguished is 2Nt-1, where Nt is the bit number of optical pulses. The device can also be used for recognition of codes encoded in time and spectral domains. Crosstalk in code recognition is discussed with numerical analysis considering AO filtering characteristics for optical processing with collinear AO devices.

This paper presents a low cost and portable DOA (Direction Of Arrival) estimation system for surveillance using a modifed beamspace MUSIC (MUltiple Signal Classification) by a quasi-orthogonal multi-beam. This is instead of DFT processing and hardware system consisting of chip-sized phase shifters, a single ADC (Analogue to Digital Converter) and a single TR (TRanceiver) module for an antenna array. In the beamspace MUSIC, generated beampatterns have orthogonal properties. This proposed system cannot make such a beampattern due to the variable range limitation of phase shifter, then we use the quasi-orthogonal beam obtained by the calculation of correlation coefficient for beampattern. We demonstrate the proposed system using 4-element microstrip array antenna and chip-sized phase shifters. The DOA experiment in anechoic chamber confirms the proposed system performance.

This paper presents a method for synthesizing a coherent 1-input 3-output optical delay-line circuit with N stages that is composed of 2(N + 1) directional couplers, N optical delay-lines, 2(N + 1) phase shifters and one external phase shifter with phase value φc . The path difference is equal to the delay time difference Δτ. Synthesis algorithm is based on the division of the transfer matrix into basic component transfer matrices and factorization is completed by repeated size-reduction. A set of recursion equations are also defined to obtain the unknown circuit parameters. In the developed method, it is shown that (13) optical delay-line circuit has the same transmission characteristics as finite impulse response (FIR) digital filters with complex expansion coefficients. Band-pass flat group delay type filter is considered as an example in this paper. It is also confirmed that developed (13) optical delay-line circuit can realize 100% power transmittance.

This letter presents an extended Pawula F-function for computing the error rate of generalized M-ary phase shift keying (MPSK) system in the presence of phase error, quadrature error, and I-Q gain mismatch over additive white Gaussian noise (AWGN) and fading channels. The extended Pawula F-function conditioned on an instantaneous fading carrier-to-noise ratio (CNR) is derived in the form of the Craig representation.

Adaptive array antennas, which control their own patterns by means of feed-back or feed-forward control, are effective tools for gain enhancement and interference suppression. However, when applying them to mobile terminals, the problems of hardware complexity and power consumption need to be taken into consideration. One solution is the use of analog device-based adaptive array antennas, such as Reactively Steered Adaptive Array (RESAA) antennas and phased array antennas, which have the attractive characteristics of low cost and power consumption. In this paper, we propose an adaptive beamforming method based on a one-dimension search algorithm for phased array antennas with Micro Electro Mechanical Systems (MEMS) phase shifters, taking into consideration their slow operating speed due to mechanical structure of the devices. Furthermore, a smoothing processing is introduced to prevent the effect of noise and a multi-resolution alogrithm is proposed to help the system form beams more quickly and stably. Numerical results based on the IEEE 802.11a Wireless Local Area Network (WLAN) standard show that the proposed method has good interference suppression and gain enhancement capabilities in multipath fading channels.

A microstrip phase shifter design that uses a reconfigurable metal pattern on the EBG ground plate is introduced. The EBG ground plate metal pattern contains a linear array of thin slots with switching devices loaded at the center. This design can vary the phase constant with minimum mismatch loss over a large frequency bandwidth. Several test ground plates without actual switching devices were used to verify the design concept.

This paper investigates intermodultation distortion in ferroelectric phase shifters depending on bias voltage. Two analog phase shifters based on barium-strontium-titantate (BST) coated sapphire substrates have been fabricated with interdigital capacitors (IDCs) which have 2 and 4 µm spacing between adjacent fingers. In case of the phase shifter with 4 µm-spaced IDCs, a phase shift of more than 121was obtained with a maximum insertion loss of 1.8 dB from 2.4 to 2.5 GHz over a bias voltage range of 0-140 V. The phase shifter with 2 µm-spaced IDCs exhibited a phase shift of more than 135with a maximum insertion loss of 2.37 dB in the same frequency range. In this case, a bias voltage of 80 V was used. Using 2 and 4 µm-spaced phase shifters, a third-order intermodulation (IM3) measurement was carried out with a two-tone cancellation setup to investigate nonlinearity, resulting in an input third-order intercept point (IIP3) of about 30.5 dBm and 38.5 dBm, respectively.

This paper discusses a generalized concept of multiple-symbol differential detection (MDD) and analytically derives weight parameters based on channel prediction for MDD on fast time-varying channels. At first, this paper shows that adaptive maximum-likelihood sequence estimation employing per-survivor processing (PSP-MLSE) with a single channel tap is similar concept to MDD. Next, the weight parameters for MDD are derived according to the channel estimation of PSP-MLSE based on a high order channel prediction. Finally, computer simulation confirms that MDD with the analytically derived parameters mitigates floor of bit error rate (BER) on fast time-varying fading channels without channel state information.

A new microstrip compatible phase shifter circuit is introduced. The phase shifter uses a strip-type electromagnetic bandgap (EBG) substrate in place of the solid metal ground plane. Such EBG substrates, when made of ferroelectric materials, can produce variable phase constants useful for phase shifter applications. Test models using two different EBG substrates with dielectric constants of 9.2 and 10.2 showed 44.5 degrees of phase difference with 1.7 dB of added insertion loss at 10 GHz from a line originally 504 degrees long.

MBF (Microwave Beam Forming) antennas are beam forming antennas that perform pattern control in RF, for a low-cost design suitable for mobile terminals. An MBF antenna has only a single output port, since this antenna consists of an array antenna, microwave phase shifters, and a power combiner. Because of this simple configuration, MBF antennas cannot adopt conventional beam forming algorithms that require both phase and amplitude control, and signal observation of each antenna element. In this paper, mutual coupling matrix estimation and null forming methods are presented for MBF antennas. It is shown that the mutual coupling matrix can be estimated by changing the antenna weight instead of signal observation of each antenna element. It is also shown that phase-only null forming, including mutual coupling effect, can be done by the optimum phase perturbations. Numerical and experimental results show the performance of these algorithms.

We describe a transmission system having a data rate of 160 Gbit/s based on the RZ-DPSK modulation format. The 160 Gbit/s single-polarization signal is generated by optical time division multiplexing technology using the base rate of 40 Gbit/s. The setup is explained and results are given with a special focus on the stability issue of the transmission system. The pulse source, the optical gate for demultiplexing, the clock recovery and the balanced photo-detector are based on semiconductor components. We present long-term bit error measurements (10 hours) over two different long-haul fiber links. The first link comprises 3106 km standard single mode fiber and uses a PMD mitigation scheme. The other link consists of 4 dispersion managed 80 km fiber spans without the need for an additional PMD compensation. Using EDFA amplification solely and also no FEC, error-free operation was achieved over several hours, only limited by slow drift effects in the laboratory system.

The High Tc SQUID was used in an unshielded environment to make eddy current nondestructive testing measurement on a multi-layer aluminum structure. As a demonstration of their capabilities, subsurface defects in a multilayer aluminum structure have been located and mapped using phase shift with no magnetic shielding around the specimen.

Phase performance in a temperature sensor using a conventional single-mode step-index fiber is studied. Two modes are excited in a so called single-mode fiber when the wavelength of a laser source is shorter than the one suggested by the specification of a fiber. The phase shift due to the temperature change of a step-index fiber is analyzed. The intensity fluctuation by the interference of two modes is observed in the experiment and estimated in the computer simulation.

A C-Ku band 5-bit MMIC phase shifter using optimized reflective series/parallel LC circuits is presented. The proposed circuit has frequency independent characteristics in the case of 180 phase shift, ideally. Also, an ultra-broad-band circuit design theory for the 180 optimized reflective circuit has derived, which gives optimum characteristics compromising between loss and phase shift error. The fabricated 5-bit MMIC phase shifter with SPDT switch has successfully demonstrated a typical insertion loss of 9.4 dB 1.4 dB, and a maximum RMS phase shift error of 7 over the 6 to 18 GHz band. The measured results validate the proposed design theory of the phase shifter.

A compact Ku-band 5-bit monolithic microwave integrated circuit (MMIC) phase shifter has been demonstrated. The total gate width of switching FETs and the total inductance of spiral inductors are proposed as the figures of merit for compactness. The phase shifter uses the T-type and PI-type high-pass filter (HPF)/band-pass filter (BPF) circuits in which FET "off"-state capacitances are incorporated as the filter elements. According to the figures of merit, the T-type is selected for 90-degree phase shift circuit and the PI-type is selected for the 45-degree phase shift circuit. The fabricated 5-bit phase shifter performs average insertion loss of 5.6 dB and RMS phase shift error of 3.77 degrees with die size of 1.65 mm 0.76 mm (1.25 mm2) in Ku-band.

This paper describes a dielectric phase shifter (DPS) using contact-less connector. As the main feature of this structure, an array of difference length strip conductor etched on a dielectric substrate placed on the microstrip patch resonators gives tightly coupling between input and output port. A sliding dielectric substrate provides phase shift for between input and output port. In this paper, the characteristics of DPS are calculated by finite difference time domain (FDTD) method, and are verified by experiments.