A tunable microstrip having removable contactless tuning stubs is used in the fabrication of a tunable T-junction circuit. Arrays of tuning stubs are formed in proximity to both sides of a microstrip signal trace. Each array of tuning stubs has a shared grounding bus connected by multiple vias to the ground plane. The sinusoidally patterned shape of the tuning stubs and their proximity to the signal trace provides a minimum breakdown voltage of 1.3 kV and a tuning sensitivity of approximately 0.01 dB to 0.02 dB.