Yusuke Uemichi

A ultra low-loss silica-based transformer between microstrip line and post-wall waveguide for millimeter-wave antenna-in-package applications

We fabricated a post-wall waveguide (PWW) into silica substrate having thickness of 520 μm and integrated a transformer between microstrip transmission line (MSL) and the PWW. The estimated loss of the transformer associated with the mode conversion and the measured loss of the PWW is 0.06 dB and 0.017 dB/mm at 60 GHz, respectively. This work would be a first attempt to apply silica substrate for microwave waveguide, to our knowledge.

Thin Film Magneto-Impedance Sensor Integrated Into

A linear magneto-impedance (MI) sensor integrated into a FePt thin film bias magnet which has in-plane isotropic magnetic property was investigated. The maximal bias field of 13.1 Oe was obtained after magnetizing a 1.3-mum thick FePt film in longitudinal direction of the sensor element. The bias field changed with the magnetizing angle. By controlling the angle in the magnetizing direction of the bias magnet and sensing direction, it was shown to be able to adjust the effective bias field after fabrication of the sensor element.

{\rm L}1_{0}

In this paper, a microstrip comb-line array antenna with parasitic elements for bandwidth enhancement at 60 GHz band is proposed. The antenna is fabricated on liquid crystal polymer (LCP) substrate due to its low dielectric loss. The antenna consists of a waveguide-to-microstrip mode transition, 16 radiation elements which construct an one-dimensional array and a terminated element. Two side-coupled parasitic elements are set symmetrically on both sides of each radiation element and an end-coupled parasitic element is set at the edge of the element for the sake of bandwidth enhancement. The antenna can be made consistently for the emerging market in the near future. Good agreement between simulated and measured results is obtained. Around 5% impedance bandwidth for |S11| less than -10 dB and 10% gain bandwidth for maximum gain over 10 dBi are finally obtained.

FePt Thin Film Bias Magnet

We propose a simple transformer between microstrip line and flexible post-wall waveguide fabricated on liquid-crystal polymer substrates. Matching to 50 Ω impedance is accomplished by a combination of blind-via and microstrip-elements. The estimated loss of the transformer associated with the mode conversion and the measured loss of the PWW is 0.6 dB and 0.9 dB/mm at 60 GHz, respectively. We also found out that the transmission property of the PWW for bending remains unchanged.

A Bandwidth-enhanced millimeter-wave microstrip comb-line array antenna with parasitic elements on liquid crystal polymer substrate

This paper presents compact and low-loss bandpass filters (BPFs) with ground-signal-ground interfaces that can easily be integrated with RFICs. The filters are realized by post-wall waveguide fabricated into a silica-substrate for the first time. A 59.11-GHz five-pole BPF with a 3.10% fractional bandwidth and a 2.62-dB insertion loss including input- and output- transitions is presented. Its intrinsic area is 8.4 mm by 2.0 mm. The proposed technology can offer practical integrated passive solutions for millimeter-wave applications.

A millimeter-wave transformer between microstrip line and flexible post-wall waveguide on liquid crystal polymer substrates

We propose a new transformer between microstrip line and post-wall waveguide fabricated on liquid-crystal polymer substrates. Matching to 50 Ω impedance is accomplished by a combination of a through-hole with an anti-pad and open-ended stubs. The bandwidth of the transformer for a reflection smaller than -15 dB is 8 GHz. The estimated loss of the transformer associated with the mode conversion and the measured loss of the PWW is 0.45 dB and 0.1 dB/mm at 60 GHz, respectively.

Compact and low-loss bandpass filter realized in silica-based post-wall waveguide for 60-GHz applications

We designed and fabricated low-loss and compact microstrip line and Marchand balun composed of thick Cu and thick resin on Si substrate for millimeter-wave applications. An attenuation constant α and Q of the fabricated microstrip line are 0.17 dB/mm and 52 at 60GHz, respectively. The insertion loss and the core size of the fabricated balun are 0.6 dB at 60 GHz and 300 µm × 450 µm, respectively, which are the lowest and the smallest among the millimeter-wave baluns ever reported, to our knowledge.

A simple millimeter-wave transformer between microstrip line and post-wall waveguide

We proposed a 60 GHz millimeter-wave platform on which several low-loss passive devices are integrated and attached to CMOS-LSI using flip-chip technology. To confirm the advantage of the platform, we fabricated passive devices of microstrip lines and a bandpass filter. We successfully obtained a low attenuation loss of 0.2 dB/mm at 60 GHz in the microstrip line. We also achieved low-loss and highly-selective bandpass filter.

Low-loss and compact millimeter-wave balun on Si

In this paper, a broadband microstrip array antenna with rectangular waveguide mode transition operating at lower E-band is proposed. The microstrip array antenna is corporate-feed structure configured by microstrip line with a mode transition from rectangular waveguide. Broadband operation can be achieved by using a slit in the transition and employing a set of feed point in the center of microstrip-line feeder which also results in fixed-beam radiation. Validity is confirmed by the evaluation of a fabricated antenna. This antenna is suitable for E-band applications such as mobile back-haul.

Low-loss millimeter-wave passives on Si

This paper presents a 60-GHz six-pole quasi-elliptic bandpass filter (BPF) realized in silica-based post-wall waveguide (PWW). We also propose a novel feeding mechanism that can control external quality factor. The mechanism has several parameters for the control. The BPF with a 8.1% fractional bandwidth and a 1.1-dB insertion loss at 60 GHz is presented. The dimension of the BPF is 3.6mm by 5.4mm.