Dielectric Phase Shifter of a Coplanar Waveguide

Investigate on the optimum height h of a dielectric phase shifter above a coplanar waveguide and edge coupled coplanar waveguide without a lower ground planeWhen two transmission lines are placed in close proximity, there is a strong interaction between their fields and power is coupled from one line to the other. In general, the amount of coupling is dependent on the distance of separation between the lines and the interaction length. An edge coupled coplanar waveguide with two parallel coupled strip conductors symmetrically located between two ground planes is shown below.

Investigate the relationship of group delay versus height of dielectric phase shifter from height = 0 to height =h above 1. A coplanar waveguide 2. An edge coupled coplanar waveguideDerive the optimize height h of a dielectric phase shifter above the GSG or GSSG to allow maximum Group Delay with a dielectric phase shifter of effective dielectric constant of 10.2 (Rogers RT6010 ) Substrate data:

Length: 5 cmWidth: 5 cmThickness h: 1 mmEffective permittivity: 10.2 (Rogers RT6010, lossless)Dielectric part: Length: 3 cmWidth: 5 cmThickness : 1 mmEffective permittivity: 10.2 (Rogers RT6010, lossless)Material: PEC (resistivity = 0), thickness t = 1 ounce of copper that is 0.035 mmWidth of Strip conductor S: select for a characteristic impedance of 50 for coplanar waveguideWidth of ground line: 5 x width of strip conductor

For edge coupled coplanar waveguideRepeat with same Width of strip conductor S as aboveAnd select d and W for a characteristic impedance of 100 for an edge coupled coplanar waveguideWidth of ground line: 5 x width of strip conductorMeasurements:

2-port S-parametersTime Delay calculated from S(1,1), mode 1Group delay calculated from S(2,1) mode 1

Frequency range: 8 GHz to 12 GHz

1. Coplanar waveguide

2. Edge coupled coplanar waveguide

h height of phase shifter above GSG = 0Vary between Height = 0 to h in order to get maximum group delay

h height of phase shifter above GSSG = 0Vary between Height = 0 to h in order to get maximum group delay