Frequency-dependent Conductor Research Articles

PROPAGATION AND RADIATION CHARACTERISTICS OF MULTILAYER COUPLED-LINE BANDPASS FILTERS USING CONDUCTOR-BACKED COPLANAR TRANSMISSION LINES

This paper presents the analytical design formulas for the bandpass filters which are built on the asymmetrically coupled-line conductor-backed coplanar transmission lines (CBCTLs) in multilayer configuration. The full-wave simulation is employed to characterize the far-field patterns of space-wave and surface-wave radiations as well as the frequency-dependent conductor, dielectric, and radiation losses. Good agreement among the results of full-wave simulation, transmission-line model, and measurement justifies the design procedure and validates the analytical design formulas. By properly placing the dielectric materials in multilayer configuration, a bandpass filter for minimizing the radiated power loss and improving the stopband characteristic can be achieved.

Attenuation mechanisms of aluminum millimeter-wave coplanar waveguides on silicon

The loss mechanisms of silicon coplanar waveguides (CPW) with aluminum metallization are investigated up to 40 GHz. Three main parts contribute to the attenuation of coplanar waveguides (CPWs): the frequency-dependent conductor losses of the metallization, frequency-independent substrate losses, and the specifically investigated bias-dependent interface losses caused by free charges at the Si-SiO/sub 2/ interface. The minimum losses found in 50-/spl Omega/ CPWs with 45-/spl mu/m signal line width were 0.19 db/mm at 10 GHz and 0.33 dB/mm at 40 GHz. High-purity silicon from a float zone (FZ) process was used as substrate. Substrates with lower purity from a Czochralski (CZ) process (resistivity 50-100 /spl Omega/cm) resulted in somewhat higher (0.2-0.3 dB/mm) losses for the same CPW geometry.

Finite-difference, time-domain analysis of lossy transmission lines

An active and efficient method of including frequency-dependent conductor losses into the time-domain solution of the multiconductor transmission line equations is presented. It is shown that the usual A+B/spl radic/s representation of these frequency-dependent losses is not valid for some practical geometries. The reason for this the representation of the internal inductance the at lower frequencies. A computationally efficient method for improving this representation in the finite-difference time-domain (FDTD) solution method is given and is verified using the conventional time-domain to frequency-domain (TDFD) solution technique.

Time-domain simulation of multiconductor transmission lines with frequency-dependent losses

A method for the time-domain simulation of multiconductor transmission lines with frequency-dependent conductor (skin effect) and dielectric losses is presented. The method is based on a traveling-wave solution of the transmission line equations in the frequency domain, which reduces to the conventional modal solution for lossless lines when no losses are present. Time-domain simulation for the lossy care is achieved by convolving the transmission line terminal voltage with describing time-domain input and transfer impulse responses for the multiconductor line. Careful formulation of the frequency-dependent conductor and dielectric losses assures causality in the transmission line responses. The numerical burden of discrete-time convolution is avoided by approximating the transmission line responses with exponential series. An implementation of the solution algorithm in SPICE is described. Examples are included for coupled lossy stripline and microstrip configurations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

High performance packaging : Ernel R. Winkler. Semiconductor Int. 350 (May 1985)

Frequency dependent conductor, dielectric and radiation losses frommuftilayer microstrp with dielectric overlay havebeencalculated using Green's function inFourier transform domain andcompared with the measured data aswell asother commercial softwares. (DasandPozar (5)) andreported elsewhere (Joshi et. al.(6)J. Radiation loss from amicrostrp resonator with dielectric overlay iscomputed using numerical data on effective permittivity. Microwave andTimedomain measurements oncharacteristic impedance, electrical length, effective permittivity andinsertion lossin microstrip withdielectric coverarereported and compared with thetheoretical results. Numerical Calculation ofLosses