the device described herein proposes an electronic active filter void of capacitors and inductors . the circuit utilizes only operational amplifiers and resistors , hence the name op - r . although capable of being constructed of lumped circuit elements this filter is intended for integrated circuit applications . filtering of signals can be accommodated from dc through the uhf frequency range depending on the selected op - amp ics . low pass , band pass , high pass , as well as band reject frequency responses are achievable . although the circuits described herein are single input - single output , multiple inputs and outputs present no difficulty , being limited only chip space . temperature and production spread variations are also considered within the realm of tenability .