Accurate Isolation Networks in Quadrature Couplers and Power Dividers

When quadrature couplers and power dividers are implemented in integrated circuits, accurate isolation networks can not be realized due to the nonideal resistors process variations. We present an network design technique which cancels resistor parasitic effects also increases tolerance variations resistance values. A Lange coupler a divider designed at Ka-band using proposed process-tolerant networks. The improvement is analytically shown empirically verified with our in-house GaN-based microstrip MMIC process. For coupler, measured return losses better than 20 dB from DC 40 GHz. achieves fractional bandwidth of 50%. Both devices maintain performance even when variation sheet as high 30%.