A new measurement technique of electrical parameters of superconducting thin films at the Very High Frequency (VHF) range is described, based on resonators with microstrip (MS) structures. The design of an optimal resonator was achieved, based on a thorough theoretical analysis, which is required for derivation of the exact configuration of the MS. A theoretical model is presented, from which an expression for the attenuation of a MS line can be derived. Accordingly, simulations were performed, and an optimal resonator for the VHF range was designed and implemented. Production constraints of YBa2Cu3O7 (YBCO) limited the diameter of the sapphire substrate to 3″. Therefore, a meander configuration was formed to fit the long λ/4 MS line on the wafer. By measuring the complex input reflection coefficients of a λ/4 resonator, we extracted the quality factor, which is mainly affected by the dielectric and conductor attenuations. The experimental results are well fitted by the theoretical model. The dielectric attenuation was calculated using the quasi-static analysis of the MS line. An identical copper resonator was produced and measured to compare the properties of the YBCO resonator in reference to the copper one. A quality factor of ~6·105 was calculated for the YBCO resonator, three orders of magnitude larger than that of the copper resonator. The attenuation per unit length of the YBCO layer was smaller by more than five orders of magnitude than that of the copper.

An RF coupler was designed and implemented using High Temperature Superconductor (HTSC) YBCO films. A circuit for a single superconducting coupling channel was implemented and serves as the primary component in a multichannel-coupling system geometry, allowing high power broadcast due to low losses of superconductors below the critical temperature ( ). In this report, a solution for the multiple antennas isolation problem is proposed by reducing the number of antennas to a single one. Multiple channel transmission systems require high power broadcasts in order to transmit signals over long distances. A coupling system with low losses was used to improve the system's active performance. In the current research the system is implemented in the VHF range using a micro-strip in meander geometry.

The growing demand for communication systems requires multi-channel solutions. However, the number of antennas in communication systems is dictated by the number of channels in each system which is limited by the available space on a broadcasting platform and by the limited available resources. We have developed a Multi-Channel Phase Control coupler in the VHF frequency range enabling a reduction in the number of antennas to a third of the original setup. The system is based on a phase shifter in a meander stripline geometry connected to each channel individually. The channels are then phase matched simultaneously to a single antenna through a computer-controlled capacitor bank connected to each phase shifter. The system performance shows a low insertion loss of 0.5 dB and a low return loss of −15 dB for the multi-channel setup.

The transmission and receiving of several channels via a single antenna is a long standing problem. We have developed a multi-channel coupler in the VHF frequency range enabling to reduce the number of antennas to one third of channels number used at one time. The system is based on a meander stripline used for each coupling channel. The channels were matched simultaneously to a single antenna using a controlled capacitor banks located on each channel. The multi coupler performance shows low insertion loss and low return loss for each channel attached to the antenna.