A Novel Simple Miniaturization Technique for Double Rat-race coupler

Compact two-position phase shifter

“…This can be determined based on the input resistance of the stub (5), where Z L -load resistance. Based on the input resistance formula, formulas were obtained to determine the input resistances of short circuit (SC) and open circuit (OC) stubs ( 6) - (7). Graphs of input resistances for short-circuit and open-circuit stubs are shown in Fig.…”

“…Therefore, compact directional coupler designs should be considered [1] - [10]. In [1], miniaturization is achieved by adding idle stubs, in [2], the branching of π-form transmission lines made it possible to reduce the size of a power divider operating at two different frequencies, in [3], [5], [10], replacing quarter-wave sections with artificial lines from high-resistance lines and stubs made it possible to obtain a compact coupler, in [4], [6], [9] defects in the screen are used, in [7], low-pass filters are used to miniaturize the coupler, in [8] to miniaturize the separator, bends of lines into the internal space of the device are used. Of course, a phase shifter on a directional coupler is not the only circuit solution for the implementation of phase shifters on a microwave substrate, so let's consider the designs of compact phase shifters, the description of which is presented in the IEEE database.…”

A compact microstrip coupler using T-shape and open stubs for fifth generation applications

“…Accordingly, high performance, small size, and inexpensive are frequently the strict conditions that must be emphasized in meeting the conditions of ultramodern wireless communication devices (7). Various approaches are used to overcome these problems and to minimize the coupler implementation, as for examples, in [8], the minimization of the size is obtained using quasi-lumped elements, a periodic capacitive load and a lumped circuit, consisting of two stubs opened with a series of transmission lines (TL ) [9], T-shaped structures [10] [11], slow wave lines [12], fractal structures [13], high-resistance lines [14], interdigitated capacitors [15], artificial transmission lines [16], the use of cascading [17], a multilayer [18], a meandering line [19], low-pass filters and planar cells [20] [21] [22] and a radial stub [23].In this paper, by combining two miniaturization methods, the compact design of the microstrip coupler is explored and further size reduction is achieved. The proposed coupler layout is adapted for operation with a center frequency of 3.5 GHz.…”

Designing a downsized quadrature directional coupler

“…The IEEE scientometric database contains a large number of works related to the miniaturization of devices [1] - [9]. In [1], miniaturization is achieved by adding idle stubs, in [2], the branching of π-form transmission lines made it possible to reduce the size of a power divider operating at two different frequencies, in [3], [5], [9], replacing quarter-wave sections with artificial lines from high-resistance lines and stubs made it possible to obtain a compact coupler, in [4], [6], defects in the screen are used, in [7] low-pass filters are used to miniaturize the coupler, in [8] to miniaturize the separator, bends of lines into the internal space of the device are used. Each approach produces its own results in miniaturizing directional couplers.…”