This paper presents a novel photonic bandgap (PBG) structure for microwave integrated circuits. This new PBG structure is a two-dimensional square lattice with each element consisting of a metal pad and four connecting branches. Experimental results of a microstrip on a substrate with the PEG ground plane displays a broad stopband, as predicted by finite-difference time-domain simulations. Due to the slow-wave effect generated by this unique structure, the period of the PBG lattice is only 0.1/spl lambda//sub 0/ at the cutoff frequency, resulting in the most compact PEG lattice ever achieved. In the passband, the measured slow-wave factor (/spl beta//k/sub 0/) is 1.2-2.4 times higher and insertion loss is at the same level compared to a conventional 50-/spl Omega/ line. This uniplanar compact PBG (UC-PBG) structure can be built using standard planar fabrication techniques without any modification. Several application examples have also been demonstrated, including a nonleaky conductor-backed coplanar waveguide and a compact spurious-free bandpass filter. This UC-PBG structure should find wide applications for high-performance and compact circuit components in microwave and millimeter-wave integrated circuits.

A uniplanar compact photonic-bandgap (UC-PBG) structure and its applications for microwave circuit

Far-field patterns and Gaussian-beam coupling efficiencies are investigated for a double-slot antenna placed on hemispherical lenses with varying extension lengths. The radiation patterns of a double-slot antenna on a silicon dielectric lens are computed using ray-tracing inside the dielectric lens and electric and magnetic field integration on the spherical dielectric surface. The measured radiation patterns at 246 GHz and Gaussian-beam coupling efficiencies show good agreement with theory. The theoretical results are presented in terms of extension-length/radius and radius/ lambda , and therefore result in universal design curves for silicon lenses of different diameters and at different frequencies. The theoretical and experimental results indicate that for single units, there exists a wide range of extension lengths which result in high Gaussian-coupling efficiencies (50-60%) to moderately high f 's. These Gaussian-coupling efficiencies can be increased to 80-90 degrees % with the use of a lambda /sub m//4 matching-cap layer. For imaging array applications with high packing densities, an extension-length/radius of 0.38 to 0.39 (depending on frequency) will result in peak directivity and a corresponding Gaussian-coupling efficiency 15-20% lower than for single units. >

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Double-slot antennas on extended hemispherical and elliptical silicon dielectric lenses

The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy (Δe), which contains at least one compound selected from the group of compounds of the formula I, II A and II B and at least one compound of the formula I* in which R0, R1, R2, R1*, X1, X2, A1, A1*, A2*, Z1, Z1*, Z2*, L1*, L2*, p, q, v, m and m* are as defined in Claim 1, and to the use thereof for an active-matrix display based on the ECB, VA, PS-VA, FFS, PALC or IPS effect.

Liquid Crystalline Medium

In this paper, inkjet-printed UHF and microwave circuits fabricated on paper substrates are investigated for the first time as an approach that aims for a system-level solution for fast and ultra-low-cost mass production. First, the RF characteristics of the paper substrate are studied by using the microstrip ring resonator in order to characterize the relative permittivity (epsivr) and loss tangent (tan delta) of the substrate at the UHF band for the first time reported. A UHF RFID tag module is then developed with the inkjet-printing technology, proving this approach could function as an enabling technology for much simpler and faster fabrication on/in paper. Simulation and well-agreed measurement results, which show very good agreement, verify a good performance of the tag module. In addition, the possibility of multilayer RF structures on a paper substrate is explored, and a multilayer patch resonator bandpass filter demonstrates the feasibility of ultra-low-cost 3-D paper-on-paper RF/wireless structures.

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RFID Tag and RF Structures on a Paper Substrate Using Inkjet-Printing Technology

With the rapid developments in very large-scale integration (VLSI) technology, design and computer-aided design (CAD) techniques, at both the chip and package level, the operating frequencies are fast reaching the vicinity of gigahertz and switching times are getting to the subnanosecond levels. The ever increasing quest for high-speed applications is placing higher demands on interconnect performance and highlighted the previously negligible effects of interconnects such as ringing, signal delay, distortion, reflections, and crosstalk. In this review paper various high-speed interconnect effects are briefly discussed. In addition, recent advances in transmission line macromodeling techniques are presented. Also, simulation of high-speed interconnects using model-reduction-based algorithms is discussed in detail.

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Simulation of high-speed interconnects

Microstrip Lines I: Quasi-Static Analyses, Dispersion Models, and Measurements -Introduction. Quasi-Static Analyses of a Microstrip. Microstrip Dispersion Models. Microstrip Transitions. Microstrip Measurements. Fabrication. Microstrip Lines II: Fullwave Analyses, Design Considerations, and Applications - Methods of Fullwave Analysis. Analysis of an Open Microstrip. Analysis of an Enclosed Microstrip. Design Considerations. Other Types of Microstrip Lines. Microstrip Applications. Microstrip Discontinuities I: Quasi-Static Analysis and Characterization -Introduction. Discontinuity Capacitance Evaluation. Discontinuity Inductance Evaluation. Characterization of Various Discontinuities. Compensated Microstrip Discontinuities. Microstrip Discontinuities II: Fullwave Analysis and Measurements - Planar Waveguide Analysis. Fullwave Analysis of Discontinuities. Discontinuity Measurements. Slotlines -Introduction. Slotline Analysis. Design Considerations. Slotline Discontinuities. Variants of Slotline. Slotline Transitions. Slotline Applications. Defected Ground Structure (DGS) -Introduction. DGS Characteristics. Modeling of DGS. Applications of DGS. Coplanar Lines: Coplanar Waveguide and Coplanar Strips -Introduction. Analysis. Design Considerations. Losses in Coplanar Lines. Effect of Tolerances. Comparison with Microstrip Line and Slotline. Transitions. Discontinuities in Coplanar Lines. Coplanar Line Circuits. Coupled Microstrip Lines -Introduction. General Analysis of Coupled Lines. Characteristics of Coupled Microstrip Lines. Measurements on Coupled Microstrip Lines. Design Considerations for Coupled Microstrip Lines. Slot-Coupled Microstrip Lines. Coupled Multiconductor Microstrip Lines. Discontinuities in Coupled Microstrip Lines. Substrate Integrated Waveguide (SIW) -Introduction. Analysis Techniques of SIW. Design Considerations. Other SIW Configurations. Transitions Between SIW and Planar Transmission Lines. SIW Components and Antennas. Fabrication Technologies and Materials.

K. C. Gupta

Papers

Microstrip Lines and Slotlines