Hai-Young Lee

Phenomenological loss equivalence method for planar quasi-TEM transmission lines with a thin normal conductor or superconductor

The incremental inductance rule for conductor loss calculations is not valid if conductor thickness decreases and becomes comparable to the penetration depth. A simple approach, referred to as the phenomenological loss equivalence method is proposed for characterizing a planar quasi-TEM transmission line with a thin normal conductor or superconductor over a wide range of field penetrations. For microstrip lines with a thin copper or high-T/sub c/ superconductor, the conductor losses calculated by this method agree very well with the published data calculated by the finite-element method and the Monte Carlo method, respectively. Because of the simplicity of the calculation, the method should be very useful for the computer-aided design of monolithic microwave circuits. >

Wideband characterization of a typical bonding wire for microwave and millimeter-wave integrated circuits

A typical grounded bonding wire with a minimum total length of 480 /spl mu/m for MMICs and OEICs is characterized using the method of moments with the incorporation of the ohmic loss as well as the radiation loss over a wide range of frequencies. The distributed ohmic resistance is calculated by an application of the Phenomenological Loss Equivalence Method. The simulated results show the wire resistance and the inductance increase greatly at frequencies above 30 GHz due to the high radiation effect enhanced by the slow-wave effect of the ohmic loss. The bonding wire is highly inductive in most of the frequency range and the maximum quality factor is mostly limited by the ohmic resistance. The results also show the simple static modeling of computer-aided design software that considers only the free-space wire inductance and the shin-effect resistance, overestimates the wire inductance at low frequencies, and is inappropriate at high frequencies due to the high radiation effect. This approach can be applied to many arbitrarily shaped interconnection wires for wideband design and characterization of high-frequency integrated circuits. >

A

In this letter, a novel power plane using an inductive S-bridged electromagnetic bandgap (EBG) is proposed for ultra wideband suppression of the ground bounce noise. The S-shaped bridge detouring unit cells effectively increase the power plane inductance. -30 dB stopband is realized from 220 MHz to 7 GHz. The stopband lower limit (220 MHz) of the proposed EBG has been greatly reduced from that (550 MHz) of L-bridged EBG. It is expected that the number of local decoupling capacitors for the power plane integrity is reduced using the proposed S-bridged EBG without the self resonance effect.

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In this letter, an elevated-coplanar waveguide (ECPW) is proposed for an intermediate section of a coplanar waveguide (CPW)-to-substrate integrated waveguide (SIW) transition. The ECPW is used to attain a gradual mode matching and to achieve the consequent wide bandwidth. The measurement results show 70% fractional bandwidth at 10 dB return loss and 0.9 dB insertion loss from 19 to 40 GHz. We expect that the proposed SIW transition plays an important role for the integration of high-Q SIW with CPW circuits, such as millimeter-wave system-in-package (SiP) using SIW circuits.

-Bridged Inductive Electromagnetic Bandgap Power Plane for Suppression of Ground Bounce Noise

Double bonding wires separated by an internal angle have been characterized in a wide range of frequencies using the Method of Moments with the incorporation of the ohmic resistance. For a 30/spl deg/ internal angle, the calculated total reactance is more than 35% less than that of a single bonding wire due to the negative mutual coupling effect of different current directions. The radiation effect at high frequencies has been observed decreasing the mutual inductance between the angled bonding wires, whereas for parallel bonding wires it greatly increases the mutual inductance. >

Ultra-Wideband CPW-to-Substrate Integrated Waveguide Transition Using an Elevated-CPW Section

A novel bandstop filter (BSF) structure is proposed and measured for wideband and compact circuit applications. The proposed BSF realizes the wide stopband (2-octave) characteristics by superposing two different photonic bandgap (PBG) structures into a coupled double-plane configuration. Only three cells of the proposed structure are enough for the measured 10 dB stopband from 4.3 to 16.2 GHz. We expect this novel BSF structure is widely used for compact and wideband circuit applications, such as compact high-efficiency power amplitiers using harmonic tuning techniques.

Parasitic impedance analysis of double bonding wires for high-frequency integrated circuit packaging

In this paper, we examined the parasitic leakage resonance of coplanar monolithic microwave and millimeter-wave integrated circuits (MMICs) by the finite-difference time-domain calculations and experiments. The results show that leakages from coplanar MMICs become significantly resonant in finite substrates and packaging enclosures. In order to avoid the leakage resonance, a resonance suppression method using a doped-Si sub-mount layer is proposed and experimented in a frequency range from 0.5 to 40 GHz. The resonance suppression scheme is verified by measuring the S-parameters of the fabricated conductor-backed coplanar waveguides having an Si sub-mount layer of different resistivities (1 m/spl Omega//spl middot/cm, 15 /spl Omega//spl middot/cm, and 4 k/spl Omega//spl middot/cm). The leakage resonance can be completely suppressed using the typical 15 /spl Omega//spl middot/cm Si sub-mount layer.

Wideband and compact bandstop filter structure using double-plane superposition

Two types of novel high-Q vertical on-chip inductors using wirebonding technology are proposed for low cost and high performance Si-RFICs. The new inductors show significant improvements of the quality factor and the self-resonant frequency. Their measured maximum quality factors are about 3-times higher than those of the planar spiral inductors (7 for 3.4 nH, 6 for 5 nH) at most. From these experimental results, the bondwire inductors are expected to greatly improve the performance and the production cost of Si-RFICs.

Suppression of leakage resonance in coplanar MMIC packages using a Si sub-mount layer

A novel high-Q on-chip inductor using bondwire loops is proposed for low cost and high performance GaAs MMIC. The measured maximum quality factor and the self-resonant frequency are 21.1 (26.5) and 11.3 (17.0) GHz for 3.5 (2.1) nH inductance, respectively. The electrical variations are measured within 5% tolerance. The on-chip bondwire inductor can be effectively used for developing GaAs MMIC with no external inductors.

Realization of high-Q inductors using wirebonding technology

Mutual coupling between grounded bonding wires for high density IC packaging has been characterized over a wide frequency range using the Method of Moments in consideration of the ohmic and radiation losses. At high frequencies, the mutual inductance greatly increases due to the radiation-enhanced mutual coupling effect. For 500-/spl mu/m-long bonding wires, a minimum 200-/spl mu/m separation is required to maintain a 20-dB crosstalk level at low frequencies. This wideband analysis will be useful for designing packages and interconnection layouts of high frequency ICs with increased packaging density and operating frequency. >