2’ x 4’ Plates readout Jean-Francois Genat March 24th 2009

2’ x 4’ plates and readout 96 T-lines at ¼” pitch Sampling chips FPGA 96 T-lines at ¼” pitch Assume 16-channel readout chips 6 chips at each side Transverse resolution > 1.8mm, any longitudinal > .5mm Clock distribution Optical output Jean-Francois Genat

Microstrip line Z0 Depends mainly on W/h http://chemandy.com/calculators/microstrip_transmission_line_calculator.htm Depends mainly on W/h Differential impedance depends mainly on s/h Zdiff = 2 * Zo ( 1 – 0.48 e-0.96s/h ) Jean-Francois Genat

Dielectric constant Trace width vs relative permittivity Z=50 Ohms, Glass thicknesses = 1 and 2mm Jean-Francois Genat

Examples e = 4.5 W=1.85mm Z=50W t=35m h=1mm Relative differential impedance (50W/Zdiff) See Tang’s slides on long lines crosstalk Jean-Francois Genat

T-line on glass Not as much experienced as ceramics Dielectric er Tan d Ceramic 4-5 1e-4 / 1e-3 PbO5 Glass 4 /15 1e-4 / 5e-3 GaAs 13 6e-4 Jean-Francois Genat