New Millimeter-Wave Fin-Line Attenuators and Switches

Analysis of FIN Line Feasibility for W-Band Attenuator Applications

“…Permittivity should be low at millimeter wave frequencies to maintain the guide wavelength large enough to alleviate any design limitations resulting from the tolerances imposed by a small guide wavelength [16]. Both copper-clad RT-duroidTM 5880 (er = 2.22) [14] and fused quartz [161 (er = 3.78) have been applied at these frequencies. Both dielectrics have good electrical properties.…”

“…This choice is based upon the numerous references [14][15][16][17][18][19][20] that work with PIN diode at W-band frequencies for control applications. The parisitics resulting from FETs generally make them unsuitable for this frequency band.…”

“…The literature indicates that multiple diodes in a fin line should be placed with quarter wavelength spacing [8, 14,16,461. Models developed in this analysis use several different criteria: minimization of the reflection coefficient, maximization of the transmission coefficient and optimization of matching in the forward bias state.…”

“…The work of others [14][15][16][17][18][19][20][21] also indicates that a fin line is a promising transmission line structure for the development of an attenuator.…”

Confirmation of Slow-Waves in a Crosstie Overlay Coplanar Waveguide and Its Application to Band-Reject Gratings and Reflectors.

“…Three commonly used definitions of the characteristic impedance (Zc) are based on where P is the transmitted power, V is the voltage across the slot, and I is the current on the transmission lines. For switching applications, the characteristic impedance based on voltage and current in the transmission line is preferred [21]. For some other applications, the power-voltage definition of characteristic impedance is used [22].…”