The MA4ST079 through MA4ST083 series of silicon hyperabrupt junction tuning varactors is produced with ion implantation and advanced epitaxial growth techniques. These diodes have thermal oxide passivation, and feature very high capacitance ratio and quality factor. They are well suited for use from the sub-HF through UHF frequency range. The standard capacitance tolerance is 10%, with tighter tolerances available. Capacitance matching at one or more bias voltages is also available.