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We present a highly integrated quasi-millimeter-wave receiver MMIC that integrates 22 circuits in a 3×2.3mm area using three-dimensional MMIC (3D-MMIC) technology. The MMIC achieves low noise (3dB) and high gain (41dB) at 26GHz by using an on-chip image reject filter. It integrates a multiply-by-eight (X8) local oscillator (LO) chain with the IF frequency of the 2.4GHz band and can use low-cost voltage-controlled oscillators (VCOs) and demodulators in a 2-3GHz frequency band. Multilayer inductors contribute to the miniaturization especially in a 2-12GHz frequency band. Furthermore, it achieves a high dynamic range by using two step attenuators with a new built-in inverter using an N-channel depression field-effect transistor (FET). The power consumption of the MMIC is only 450mW.

Newly developed multi-layer inductors on GaAs three-dimensional MMICs are presented. We analyzed single-, double-, triple-, and quadruple-layer stacked-type inductors in what may be the first report on inductors on a GaAs MMIC with three or more layers. The performance of single- and multi-layer inductors was measured and calculated by electromagnetic field simulation. The multi-layer inductors produce 2-11 times higher inductance than that of conventional inductors on 2D-MMICs although they are the same size. This means that the proposed multi-layer inductors have smaller areas with the same inductances than those of conventional inductors. We also conducted the first-ever investigation of how performance factors such as parasitic capacitance, Q-factor, and self-resonant frequency are degraded in multi-layer inductors vis-a-vis those of conventional inductors. A microwave amplifier using multi-layer inductors was demonstrated and found to reduce circuit size by 20%.

SUMMARY A highly integrated frequency quadrupler MMIC that uses three-dimensional MMIC (3D-MMIC) technology is presented. It consists of four driver amplifiers, two doublers, and a 2-band elimination filter. These seven circuits are integrated in only a 2.36 mm2 area. The filter sufficiently suppresses spurious output components. The third and fifth harmonic components, which are the spurious components nearest to the desired component, are well suppressed. The desired/undesired ratio is about 40 dB. The driver amplifiers make the quadrupler output a constant power of the desired multiplied signal under low input power. The MMIC supplies +5 dBm of the fourth harmonic component in the input power range from −10 dBm to +5 dBm. The power dissipation of the MMIC is only 160 mW.

This paper describes a miniaturized in-phase power divider with a DC block function. We first propose three types of miniaturized in-phase power dividers composed of two distributed transmission lines, a resistor, and three capacitors to function as a DC block. Then, we use a simulation to compare the dividers. The simulation results show that, by properly selecting circuit configuration, we both achieve broadband frequency characteristics and miniaturize circuitry as compared to the conventional Wilkinson power divider with two DC block capacitors. Finally, an experimental UHF power divider fabricated to test the design concept is presented. Over the frequency range from 0.44 to 0.66 GHz, the experimental power divider exhibits power splits of -3.2 ± 0.2 dB, return losses greater than 20 dB, and isolation between output ports greater than 20 dB.

This paper describes a broadband active terminal circuit and its application to a distributed amplifier. In this study, we first analyzed and compared three types of active terminal circuits using representative circuit configurations, namely, an active terminal circuit with a commonemitter BJT, an active terminal circuit with a Darlington BJT pair, and an active terminal circuit with cascode-connected BJTs. The simulation results showed that the active terminal circuit with cascode-connected BJTs kept the matching condition up to high frequency. After the simulation, we fabricated a distributed amplifier that used an active terminal circuit with cascode-connected BJTs. The RF amplifier achieved a flat gain of 9.7±1.0dB over a range of 3-15 GHz.

This paper describes miniaturized broadband lumped-element in-phase power dividers. We first propose two types of miniaturized broadband lumped-element in-phase power dividers composed of two inductors, a resistor, and two capacitors. Next, we use a simulation to compare these dividers with conventional power dividers. The simulation results reveal that the proposed lumped-element in-phase power dividers can help miniaturize circuits (by decreasing inductances by about 30%, reducing the number of necessary capacitors by half, and decreasing necessary capacitances by about 30% as compared to conventional lumped-element dividers) and attain broadband frequency characteristics (by increasing normalized operating frequency bandwidths (f/f 0 ) by about 80% as compared to conventional lumped-element dividers).

A broadband, low-noise, wide dynamic range front-end receiver IC is reported. It uses 0.25 μm SiGe BiCMOS process technology and consists of broadband variable gain low noise amplifiers (VGLNAs), down-conversion mixers, step attenuators, and buffer amplifiers. It can receive triple-band signals concurrently, and the chip size is only 3mm × 3mm. Its measured noise figure was under 3.2 dB and the measured conversion gain was around 30 dB in the broad frequency range from 300 MHz to 3 GHz. It has a wide gain control range of around 100 dB; 50 dB is controlled by the VGLNA and the step attenuator, and 50 dB by the mixer with novel relative power control method using dual LO signal. The gain control enhances the input 1dB compression point from -40 dBm to -21 dBm.

The Multi Sector Monopole Yagi–Uda Antenna (MS-MPYA) can be used to realize low profile, multi-sector antennas. The MS-MPYA has an interesting feature; we can sharpen the beams by using the adjacent array effect if we set metallic fins between the arrays so as to hide the excitors. Otherwise, without the fins, undesired radiation from the adjacent arrays causes beam division. This paper shows the radiation mechanism by using transient solutions in the time domain calculated by the FDTD method to examine how electromagnetic waves interact with the directors, adjacent arrays, and fins in real time. We introduce the transient solutions for three types of MS-MPYA: with adjacent array and with fins, without adjacent array but with fins, and with adjacent arrays but without fins. The transient solutions show that the adjacent array's action is changed by the existence of the fins and caused beam division. Without fins, the adjacent arrays act as directors of the active array and cause beam division. With fins, the adjacent arrays reflect the wave coming from the main array and sharpen the beam. Copyright © 1999 John Wiley & Sons, Ltd.

Since the 1980s, NTT has been developing three-dimensional (3D) monolith microwave integrated circuits (MMICs) to achieve small-size and low-cost ICs. The usage of 3D MMICs is a very powerful technique, especially at quasi-millimeter and millimeter wave levels. We describe the structure and features of 3D MMICs, introduce several MMIC subsystems, and point out future directions and plans for using 3D MMICs.

In microwave frequency bands, we have found that the application of spatial division multiplexing (SDM) using a number of antenna arrays is particularly effective for short transmission distances. We were also able to raise channel capacity in short-distance communication to several hundred Gbit/s by utilizing parallel transmission over a 60-GHz band with its wide bandwidth. When utilizing this technology, displacement of TX and RX antennas occurs because of the need to adjust the position of antennas manually by users. Antenna displacement causes deterioration in channel capacity. Electromagnetic field analysis results clarified the impact on channel capacity of antenna displacement that occurs in short-range transmission applications. Our results showed that channel capacity degradation is 10% when the horizontal antenna displacement is 1.5 mm and channel capacity degradation is only 2.7% when the rotational antenna displacement is 10°. The channel capacity degradation is smaller with longer transmission distances.

Various technologies have been put to practical use for high-speed wireless communications systems. For short transmission distances, we have found that the application of spatial parallel transmission using a number of antenna arrays is particularly effective in microwave frequency bands. This report describes how we were able to raise channel capacity in short - distance communication considerably by utilizing parallel transmission over a 60-GHz band with its wide bandwidth on the basis of electromagnetic field analysis results. We also clarified the impact on channel capacity of antenna displacement that occurs when placing the antennas. Our results showed that the channel capacity obtained using 20 mm × 20 mm antenna arrays is more than 1,000 Gbit/s when the transmission distance is 1 mm and that channel capacity degradation is 5% when the antenna displacement is 1 mm. The degradation becomes smaller with longer transmission distances.

A compact GaAs pHEMT monolithic microwave integrated circuit balanced frequency doubler is presented. It is composed of a common-source/common-gate active balun, a balanced frequency doubler, and a band pass filter. Excellent miniaturization is achieved by using double-and triple-layer stacked inductors and a miniaturized stub as a band-pass filter with a thin-film microstrip line. The chip size is only 0.95 mm × 1.05 mm and power consumption is 63 mW. The measured conversion gain is −4 dB, and the fundamental and 3rd order frequency leakage to the 2nd order harmonic signal are less than −25 dB and −35 dB respectively.

Recently, system studies and hardware investigations on wide area ubiquitous network systems have been conducted. In this paper, we propose a compact sector antenna structure based on a co-linear array antenna that employs phase-difference feeding for a suitable base station in a wide area ubiquitous network system. In order to reduce the element interval with the goal of miniaturizing the sector antenna, we clarify the antenna feeding conditions while considering the mutual coupling between elements. Moreover, to achieve the proposed antenna structure, we employ a vertically arranged offset configuration that suppresses the influence on the radiation characteristics to 0.5λ o . To verify the antenna design, we developed a prototype antenna for the VHF band. We confirm that the measured results are in good agreement with the calculated results.

A highly integrated quasi-millimeter-wave transmitter MMIC that integrates 26 circuits in a 3 mm times 3 mm area using three-dimensional MMIC (3D-MMIC) technology is presented. The power dissipation of the MMIC is only 0.54 W. It achieved a high P1 dB of 6 dBm and gain of 19 dB at 26 GHz. Furthermore, it integrated step attenuators with a new built-in inverter using an N-channel depression FET for transmit power control.

Newly developed multi-layer inductors on GaAs three-dimensional MMICs are presented. We tested single-, double-, triple-, and quadruple-layer stacked-type inductors in what may be the first report on inductors on a GaAs MMIC with three or more layers. These proposed multilayer inductors can produce higher inductance in the same area as conventional 2D-MMICs. The performance of the single-and multilayer inductors was measured on wafer and calculated by electromagnetic field analysis using the finite element method. Though they are the same size, the multilayer inductors produce 2~11 times higher inductance than the single-layer inductors. In addition, the degradation of the multilayer inductor performances, such as resistance, Q-factor and self-resonant frequency, was not seen compared with the single-layer inductors. Multilayer inductors make it possible to shrink circuit size from many hundreds of MHz to the millimetre wave.

We propose a broadband low noise amplifier with high linearity performance. The amplifier achieves broadband, low noise performance and high linearity using a bias circuit with high impedance. The bias circuit consists of an inductor, a resistor, and a current source. The circuit obtains high impedance using a high resistive component. From 0.8 to 5 GHz, the low noise amplifier shows an S21 of 20plusmn1 dB and an S11 of less than -9 dB. The noise figure is 1.5-2.7 dB for frequencies from 0.5 to 5 GHz. The output 1-dB compression point at 2 GHz is +6.3 dBm.

A highly integrated X-band frequency quadrupler MMIC using three-dimensional MMIC (3D-MMIC) technology is presented. It consists of four amplifiers, two doublers, and a 2-band elimination filter. These seven circuits are integrated on only a 2.25 mm times 1.05 mm chip. The third and fifth harmonic components, which are spurious components nearest to the desired component, are well suppressed. The desired/undesired ratio is about 40 dB. The MMIC supplies +5 dBm of the fourth harmonic component at input power as low as -10 dBm. The power dissipation of the MMIC is only 160 mW.

A highly integrated quasi-millimeter wave receiver chip that integrates 22 circuits on a 3 x 2.3 mm chip using three-dimensional MMIC (3D-MMIC) technology is presented. The receiver MMIC operates with an LO signal in the 2.7-3.1 GHz range. This LO signal is multiplied in an integrated multiply-by-eight (X8) LO chain, resulting in an IF center frequency of 2.4 GHz. It can use low-cost VCOs and demodulators in a 2-3 GHz frequency band. The power dissipation of the MMIC is only 450 mW. It also achieved low noise (3.4 dB) and high gain (41 dB) at 26 GHz. Furthermore, it achieved a high dynamic range using two step attenuators in the RF and IF frequency bands with a new built-in inverter using an N-channel depression FET.

The authors propose a dual-band VCO integrated with RF-MEMS devices using flip-chip mounting. A wide frequency band switching capability is realized using low-loss RF-MEMS switches and high-Q inductors to switch one of series-connected inductors. A VCO with RF-MEMS was fabricated and measured. The carrier frequency of the dual-band VCO was tuned from 4.443 to 4.695 GHz and from 5.106 to 5.411 GHz. The phase noise was -103 dBc/Hz at a 1-MHz offset from the carrier frequency of 4.443 GHz

The growth of mobile communication has been very rapid and people can call from everywhere even in moving vehicles. Another trend is that personal computers (PCs) are becoming indispensable communication tools for business. Naturally, people desire to communicate through PCs even from outdoors, and research has considered wireless computer communication. One technical problem of wireless computer communication is how to realize a small efficient antenna for installation on a wireless IC-card. There have been some antennas reported. However, the only one that can be integrated into an IC-card is installed on the face of the IC card, so its performance degrades when it is inserted into the card-slot. We propose a new type of antenna for an IC-card which can be seen through the aperture of the card-slot. Since this antenna consists of two radiation elements which radiate V-polarization and H-polarization beams, it has a good performance regardless of the terminal inclination. This paper describes the configuration of the proposed antenna and its performance and shows its feasibility as a 2 GHz wireless system antenna.

This paper proposes a three-dimensional active antenna configuration for a front-end module of a high-speed wireless communication system at millimeter and quasi-millimeter-wave frequencies. The active antenna is integrated with a microstrip antenna array on multilayer alumina-ceramic, individual MMIC chips including transmit/receive amplifiers, time division duplex switches, and a filter on multilayer polyimide. The three-dimensional structure achieves an unrestricted RF-circuit design on multilayer polyimide.