Unified Description of Coupled Resonators and Coupled Transmission Lines

Abstract

Coupled resonators and coupled transmission lines are described with the same coupling curve. A ratio between resonant frequencies, squared, of coupled resonators and ratio between impedances of coupled transmission lines reveal the same type of dependence on coupling coefficient. This can be used to select, adjust or create the models of coupled structures. As an example the new model of coupled transmission lines has been developed. Its application in LC element directional coupler is presented and discussed.

A Resonator Enhanced UHF RFID Antenna Cable for Inventory and Warehouse Applications

“…With longer cable and 20 resonators, insertion loss indicated that resonators were tuned to multiple frequencies. This happens because two coupled resonators (or resonant circuits) have two resonant frequencies and having strong coupling between the resonators leads to increased differences between the resonant frequencies [29] which is seen with the 20resonator cable, Case 4.…”

Compact Dual Bandpass Filter Using Dual-Split Ring Resonator for 5G Upper Microwave Flexible Use Services

“…Two dual-split ring resonators were coupled along the transmission line and resonated at two resonant frequencies (also called eigenfrequencies). The strength of coupling is expressed using the coupling coefficient, which can be calculated from the following formula [11]:…”

“…Some of the filter structures that apply coupled transmission lines act as coupled resonators. Researchers are taking advantage of coupled resonator theory to design new models of coupled transmission lines [11]. Metamaterial structures can exhibit novel electromagnetic properties at microwave and millimeterwave frequencies that cannot be obtained using conventional materials.…”

Coupled‐line proximity‐coupled microstrip linear array antenna for millimetre‐wave applications

“…Under these conditions, the even and odd modes and their reflection coefficients are complementary, so that the impedance at all frequencies at the input port are matched [25]. Abramowicz[26] showed the importance of Z 0e and Z 0o and how they affect the coupling coefficient K between the two lines, as shown in (8) as When K is small the impedances are close to that of an uncoupled line. When the strength of the coupling increases the difference between the impedances becomes larger.…”