Hiroyuki Yabuki

Dual-mode stepped-impedance ring resonator for bandpass filter applications

It is well known that two orthogonal resonant modes exist within a one-wavelength ring resonator. In this paper, we focus on a ring resonator possessing an impedance step as a form of perturbation. A convenient analyzing method for obtaining the resonance characteristics of this resonator structure is presented. Furthermore, generation of attenuation poles obtained by the dual-mode ring resonator is discussed. In addition, a filter design method based on this resonator is explained, followed by experimental results, which prove the validity of the proposed design method.

Stripline dual-mode ring resonators and their application to microwave devices

This paper describes the fundamental properties of two orthogonal resonant modes within stripline ring resonators and their application to microwave devices. There are two principal methods for application of ring resonators, the first is by using two-port devices and the second four-port devices, in the case of two-port configurations, dual-mode filters using coupling between two degenerate modes have been studied as typical applications. In this paper, new methods for the coupling of two modes and their applications to practical devices, are proposed, and then experimental results for proof of the new structures are presented. Four-port configurations, which make use of two resonant modes as being independent or having no coupling between them, have a wider range of application to microwave devices. Microwave circuits such as tuned amplifiers and oscillators with novel structures are proposed, and their excellent characteristics are demonstrated. The experimental results obtained in this study on two and four-port devices make it clear that dual-mode ring resonators have great potential for application to various microwave devices.

Voltage controlled push-push oscillators using miniaturized hairpin resonators

The authors describe the fundamental characteristics of compact stepped impedance hairpin resonators with parallel coupled lines, and show their application to voltage-controlled push-push oscillators for UHF band operation. The experimental push-push oscillators built using these resonators provide low phase noise and wide tuning operation.<<ETX>>

Packaging using microelectromechanical technologies and planar components

A novel millimeter-wave packaging structure was developed in which a micromachined low-loss planar component and flip-chip devices were integrated on a silicon substrate. A low-loss planar filter was achieved on a 7-mm-square silicon substrate employing an inverted microstrip line and a unique resonator. High attenuation in the stopband was also obtained by introducing a pole control technique. Fabrication of a compact K-band receiver front-end incorporating a built-in filter was realized using multilayered benzocyclobutene (BCB) and flip-chip bonding techniques. Furthermore, we propose an alternative BCB suspended structure and demonstrate a planar antenna for Ka-band applications. These technologies bring to reality high-performance compact packaged systems in millimeter-wave region applications.

The design of a half-wavelength resonator BPF with attenuation poles at desired frequencies

A design method for a planar band-pass filter with attenuation poles based on a half-wavelength resonator is proposed. According to this design, the attenuation poles can be obtained at any desired frequency by means of coupling structures. Therefore, a filter with excellent attenuation characteristics for various applications can be achieved.

New type of push-push oscipliers for the frequency synthesizer

The authors describe the fundamental principles of novel voltage-controlled push-push oscipliers (oscillator/doubler) and show their application to a frequency synthesizer for L-band operation. The push-push oscipliers had 2 output ports. By means of a 0 degrees hybrid circuit, the external output power was obtained and the fundamental frequency was adequately suppressed at the same time. By applying the fundamental frequency, which was derived from a 180 degrees hybrid, to a prescaler of a phase-locked loop, the RF input power and the DC power consumption of the frequency synthesizer were reduced. The experimental frequency synthesizer had the advantages of high-frequency operation, compact size, and low power consumption.<<ETX>>

K-band receiver front-end IC integrating micromachined filter and flip-chip assembled active devices

A novel three-dimensional K-band receiver front-end IC was developed in which a micromachined low-loss filter and flip-chip devices ware integrated on a silicon substrate. An inverted microstrip line and a new resonator are newly introduced in the filter. Multilayered BCB and flip-chip bonding technologies are also adopted.

A Ka-band high-efficiency dielectric lens antenna with a silicon micromachined microstrip patch radiator

Novel antenna configurations suitable for millimeter-wave applications were proposed incorporating a dielectric lens antenna with a single microstrip patch radiator. In general high aperture efficiencies are easily obtainable with lens antennas because of flexibility in controlling the aperture-field distribution coupled with low feeder loss. The radiator was integrated with front-end circuits into a single hybrid IC using silicon micromachining and BCB (benzo-cyclobutene) multi-stacked circuit processes. The radiator was constructed on a thin suspended BCB film to suppress dielectric and conductor loss. A demonstration radiator showed good performance at 39 GHz (Ka-band). The lens was designed using geometrical optics relative to the directivity of the radiator and the aperture-field distribution. The circular polarized lens antenna assembly exhibited a gain of 15.7 dBi, 18.7 dB side-lobe level suppression and 0.17 dB axial ratio.

Miniaturized stripline dual-mode ring resonators and their application to oscillating devices

Novel structures of miniaturized stripline Dual-Mode Resonators (DMRs) have been proposed, and their fundamental properties related to orthogonal modes are analytically derived. DMRs have attractive features which will provide many distinctive oscillating circuits. Experimental oscillating devices such as oscipliers and low phase noise voltage controlled oscillators using miniaturized DMRs are expected to have a practical use for various kinds of radio equipment in the RF and microwave regions. Moreover, this design concept is applicable for millimeter wave oscillators or smaller.<<ETX>>

Packaging using MEMS technologies and planar components

Three-dimensional millimeter-wave IC applying multi-layer BCB thin film and silicon micromachining technology was developed. Low loss characteristics were achieved by applying micromachining technology, despite being a quasi-planar structure, and a K-band filter was developed. Moreover, manufacture of the receiver front-end with built-in filter integrated into one package was realized by using flip-chip bonding techniques. Furthermore, we proposed an alternative BCB suspended structure and demonstrated a Ka-band antenna for the proposed package.