The electric field tuning characteristics of a combined microwave resonator based on ferrite-ferroelectric layered structure have been studied in a wide range of bias magnetic fields. The combined ferrite-ferroelectric resonator was composed of two rectangular resonators fabricated from a ceramic barium strontium titanate (BST) slab and a single-crystal yttrium iron garnet (YIG) film. The in-plane dimensions for the YIG and BST resonators were chosen to be equal in order to maximize the electromagnetic coupling between their main modes and reduce spurious influence of their higher order modes. A tuning range of $100\mathrm{MHz}$ for the resonator frequency was realized at $5\mathrm{GHz}$ through the variation of magnetic permeability and dielectric permittivity of the YIG-BST structure. A theory for the hybrid wave excitations, based on a coupled-mode approach, has been developed and provides good description of the data.

A cost-effective way of reducing sidelobe level and improving front-to-back ratio of the substrate integrated waveguide H-plane horn antennas is proposed in this letter. Metal rectangular patches and dielectric loading are integrated to the aperture of the horn antenna, resulting in an increased gain, narrow E-plane beamwidth, and reduced sidelobes and backward radiation. The overall dimensions of the fabricated antenna are 42 × 18.6 mm ² . The antenna works at 22.7 GHz with a measured gain of 10.1 dBi. A single substrate and a 3.5-mm connector with a transition pin are used to ensure the lowest cost for mass production.

Measurements of the linear (Pockels) electro‐optical coefficient of wurtzite GaN are reported. The values for the electro‐optic coefficients r₃₃ and r₃₁ are 1.91±0.35 and 0.57±0.11 pm/V at 633 nm, respectively, in agreement with extrapolations from measured second‐harmonic generation coefficients (χ₃₃⁽²⁾=−20±6 pm/V and χ₃₁⁽²⁾=10±3 pm/V) suggesting that the dominant contributions are electronic in origin. Measurements were performed using a Mach–Zehnder interferometer with LiNbO₃ as a reference material. Piezoelectric effects were also observed.

This paper presents a simple, low-cost, hours-long fabrication method for microwave waveguide components of high RF performance. The technique combines 3-D-printed configurations with liquid metal waveguide structures. As a demonstration, a fused deposition modeling multimaterial 3-D consumer-grade printer and liquid gallium were used. A conductive polylactic acid (PLA) waveguide flange was 3-D printed along, in-one-go, with standard PLA for the rectangular waveguide liquid metal enclosures. Microwave WR62 waveguides, resonators, and filters operating in Ku-band were designed, fabricated, and tested. The RF performance of the fabricated waveguide devices is in agreement with the simulations demonstrating better than 1.29 dB/m attenuation in the waveguide and better than 1000 Q-factor for the resonator and the filter at 13 GHz. The fabricated devices demonstrate a new option of an economical fabrication technology for high RF performance microwave waveguide-based devices that can be delivered in hours-time, anywhere, anytime with minimal equipment deployment and investment.