Hao-Tian Zhu

Wideband In-Phase and Out-of-Phase Balanced Power Dividing and Combining Networks

Two new wideband in-phase and out-of-phase balanced power dividing/combining networks are proposed in this paper. Based on matrix transformation, the differential-mode and common-mode equivalent circuits of the two wideband in-phase and out-of-phase networks can be easily deduced. A patterned ground-plane technique is used to realize the strong coupling of the shorted coupled lines for the differential mode. Two planar wideband in-phase and out-of-phase balanced networks with bandwidths of 55.3% and 64.4% for the differential mode with wideband common-mode suppression are designed and fabricated. The theoretical and measured results agree well with each other and show good in-band performances.

MICROSTRIP WIDEBAND BANDPASS FILTER WITH SIX TRANSMISSION ZEROS USING TRANSVERSAL SIGNAL-INTERACTION CONCEPTS

A high-selectivity microstrip wideband bandpass fllter with six transmission zeros using transversal signal-interaction concepts is proposed. A flfth-order wide passband with six transmission zeros (0{2f0, f0 is center frequency of the passband) can be realized two transmission paths. The bandwidth and locations of the transmission zeros can be adjusted conveniently by changing the characteristic impedances of open stub and coupling coe-cients of the open/shorted coupled lines. A prototype of planar wideband bandpass fllter with 3-dB fractional bandwidth 43.3% (2.33{3.63GHz) is designed and fabricated. The measured and simulated results both indicate good performances of high selectivity and wideband harmonic suppression.

A transition of microstrip line to dielectric microstrip line for millimeter wave circuits

A compact microstrip line to dielectric microstrip line (DML) transition is investigated, where DML is a dielectric waveguide that has quasi-planar structure line like conventional microstrip. DML is much more convenient to be used for various circuit constructions, comparing to other dielectric waveguides such as non-radiative dielectric guide and image guide. However, DML is not a standard transmission line. Transition is required for the measurement. In our experiment, the measured insertion loss of a section of DML with two back-to-back transitions ranges from 3.1 dB to 5.3 dB during 42 GHz to 54 GHz.

A 750–1000 GHz

A wideband THz H-plane dielectric horn antenna based on silicon (Si) technology is proposed in this paper. The antenna can be integrated with the planar structure circuit and the dielectric ridge waveguide. To fabricate the proposed antenna, the deep reactive ion etching high-resistivity Si fabrication process is used. The size of the proposed antenna is 3.13 × 4 × 0.1 mm3. The operating frequency of the antenna ranges from 750 to 1000 GHz, which corresponds to a fractional impedance bandwidth of 28.6%. The antenna has a narrow beamwidth in the H-plane and a high gain. To test this antenna, the characterization of the metal waveguide diagonal horn for measurement is analyzed. Then the non-contact measurement method is applied to measure the designed dielectric horn. The simulated radiation efficiency of the antenna is higher than 80% while the measured gain of the antenna is larger than 8 dBi. Measured H-plane radiation patterns from the proposed antenna are presented and show reasonable agreement with the simulated results.

H

In this paper, dielectric ribbon waveguides (DRWs) are designed to work at 750-1000 GHz. In this frequency band, the Deep Reactive Ion Etching (DRIE) of high resistivity silicon fabrication process is selected to fabricate the DRW. Our experiments show that the average attenuation constant of DRW is merely 0.107dB/mm at 750-1000GHz. Good agreements between the measured and simulated results are observed.

-Plane Dielectric Horn Based on Silicon Technology

In this paper, four types of silicon based THz dielectric waveguide are introduced. The silicon based THz dielectric waveguides are all fabricated by DRIE technology. The losses of these dielectric waveguides are very low.

Low loss dielectric ridge waveguide based on high resistivity silicon for E 11 y Mode Propagation at 750–1000GHz

A low-loss dielectric microstrip line (DML) integrated circuit based on silicon (Si) technology is proposed for THz applications in this paper. Using the DML, a coupler and a crossover are designed. In the proposed technology, all THz passive components are made of high-resistivity silicon on insulator (SOI) wafer. To fabricate the proposed transmission line and its components, we developed a high-precision fabrication process for the SOI wafer. A non-contact measurement technology is used to test the fabricated samples. The measured loss per wavelength of DML ranges from 0.0082 to 0.042 dB/λ over 750-925 GHz. The measured isolation of the crossover is 25.45 ± 5.54 dB, and the measured coupler factor of the coupler is -13.22 ± 3.23 dB.

Silicon based THz dielectric waveguides

This paper presents a multilayer dielectric transmission line - the dielectric microstrip line (DML), for the terahertz (THz) applications. This DML is a metal free transmission line eliminating metal loss, which can be a very serious problem at THz. The Ey11 mode is the main mode in the DML for the electromagnetic wave propagation. A DML with standard waveguide operating within 0.220THz-0.325THz is designed, fabricated and measured for demonstration. With TRL calibration method, phase constant and attenuation constant of the DML are obtained.

Design, Fabrication, and Measurement of the Low-Loss SOI-Based Dielectric Microstrip Line and its Components

We investigated a dielectric transmission line consisting of three dielectric substrate layers for millimeter-wave (mmW) applications. This line is referred to as a narrowed dielectric microstrip line (N-DML). The effective dielectric constant method is used to analyze the propagation characteristics of the N-DML. The result of the analysis of the normalized phase constant is consistent with the simulation. For demonstration, two

Dielectric microstrip line (DML) — A new transmission line for terahertz applications

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