The method of designing stub quadrature couplers with reduced dimensions relative to the standard design is considered. This technique is based on replacing quarter-wave sections of a microstrip transmission line (MTL) with low-pass filters (LPF), with equivalent frequency characteristics in the vicinity of the central frequency of the device. In addition, the circuit and design implementations of compact couplers with a controlled operating frequency and different wave impedances of the supply lines of the coupler are considered.