In this paper, we present the design, simulation, fabrication, and measurements of an on-chip dielectric resonator (DR)-fed millimeter-wave high-gain antenna system with in-antenna power combining capability. A low-profile resonant cavity antenna is fed by four spherical DR, showcasing the antenna’s multi-feed capabilities. Each DR is fed by two microstrip resonators located diagonally opposite on a planar circuit board and are excited via coaxial connectors. The design incorporates a printed partially reflecting superstrate, reducing the antenna’s overall size and profile while simultaneously enhancing directivity by approximately $10\,\mathrm{dB}$ at the design frequency of $30\,\mathrm{GHz}$. The antenna exhibits wideband matching. Key performance metrics, such as directivity, gain, beamwidth, and bandwidth, predicted by full-wave electromagnetic simulations align well with the results from experimental measurements.

In this paper, a simple and efficient method to increase the gain and bandwidth of the wearable antennas used in several medical/communications systems is presented. To increase the gain and bandwidth simultaneously, the triple transmission lines (TTLs) method has been used. With this method, the frequency ranges of 1.7–2.5 and 5.4–5.95 GHz are covered with dual-band responses. Also, the simulated maximum gain at 2 and 5.8 GHz is equal to 8.26 and 9.86 dB, respectively. Using the TTLs method, the second frequency band (5.4–5.95 GHz) is achieved. Also, the gain improvement in operating frequencies is more than 4 dB compared to the conventional antenna. The dimensions of the proposed wearable high-gain antenna are 80 × 92 × 2 mm3 or 0.57 × 0.67 × 0.01 λg3 at 2 GHz. Finally, a dual-band sample antenna for use in medical systems was fabricated with a flexible felt substrate and its characteristics were measured. There is a good fit between the measurement and simulation results.

A bottom-feed omni-directional CP (circularly polarized) antenna array is proposed in this letter. The antenna array is composed of four elements (two printed ZPS (zero-phase-shift) line loops and two half-wavelength dipoles). The four elements are fed with the same phase and amplitude. The ZPS line loops provide the horizontal polarization while the dipoles provide the vertical polarization. Therefore, omni-directional circular polarization is formed in the far field. The feeding network consists of a 1–4 T-shaped power divider formed by parallel strip lines. In order to balance the amplitude of the feeding coaxial cable, the structure is used in the bottom to transfer parallel strip line to micro-strip line. Besides, the loops and the dipoles are placed on the different side of the network to guarantee the omni-directional radiation property. The measured impedance bandwidth of the fabricated antenna is 0.13 GHz (2.40–2.53 GHz) and the measured maximum CP gain at 2.45 GHz is 4.8 dBic.

In this paper, high-gain cavity backed patch antenna arrays are proposed based on low temperature co-fired ceramic technology at 140 GHz. By introducing a substrate integrated cavity to the patch antenna element, the gain is enhanced by 3.3 dB. Moreover, a rectangular ring is loaded around the patch for better impedance matching and further gain enhancement. The final simulated maximum gain of the proposed antenna element is 9.8 dBi. Based on the proposed high-gain antenna element, a 4 × 4-element array and an 8 × 8- element array are presented. The 4 × 4-element array shows a measured maximum gain of 16.9 dBi with 9.5 GHz bandwidth (136.2–145.7 GHz) and the 8 × 8-element array shows a measured maximum gain of 21.8 dBi with 9.8 GHz bandwidth(136.7–146.5 GHz), respectively.