This letter proposes a novel capacitively coupled microstrip comb-line array (CCMCA) antenna for millimeter-wave band applications. The proposed antenna has the advantages of low profile, low cost, and ease of fabrication for the millimeter-wave band. By adjusting the gaps between the radiating strips and feeding line, an antenna with low sidelobe level can easily be designed. To verify the suitability of the proposed antenna for millimeter-wave applications, two arrays (1 x 18 and 4 x 18) were designed and developed at the design frequency of 79 GHz. The measured results show good agreement with the simulated ones in terms of reflection characteristics and radiation patterns. In addition, the CCMCA antenna has stable beam direction even with frequency change, compared to a conventional series-fed microstrip rectangular patch array antenna.

This paper proposes a millimeter-wave series-fed coupled split-ring resonator array (SCSRRA) antenna with a wide fan-beam pattern and low sidelobe level (SLL) for automotive radar. The proposed array antenna has the advantages of low cost, low profile, and low manufacturing difficulty. The proposed array antenna uses a split-ring resonator as a radiating element coupled from a microstrip line. The split-ring resonator has the advantage of suppressing cross-polarization due to feed phase errors. To reduce the surface wave through the ground edges and enhance the beamwidth, we added the mushroom-shaped electromagnetic bandgap (EBG) structure. Amplitude tapering to reduce the SLL was implemented by adjusting the distance between each element and the microstrip line. The prototype SCSRRA antennas operating at 79 GHz were fabricated, and the characteristics of the wide fan-beam pattern and low SLL were experimentally verified.

We developed an implantable electrocardiogram (ECG) monitoring system and demonstrated its performance through an in vivo test. In the system, the implantable device senses not only the ECG signal of the animal but also the voltage level of the secondary cell and temperature inside the implantable device, and users can check the transmitted information through a PC program or a mobile application. The adoption of wireless charging technology eliminates the use of a lead wire and repetitive surgery to replace the implantable device. The proposed wireless charging technology demonstrated experimentally a wireless power transfer efficiency of approximately 30%. To minimize the size of the implantable device, the antenna and coil were integrated into a size of 34 mm × 14 mm. Communication between the implantable device and the basestation can reach up to 2.4 m when the implantable device is inserted into a porcine skin sample.

This paper presents a microstrip comb-line array antenna for the low sidelobe level (SLL) in the millimeter-wave. As the width of the conventional stub-shaped radiating element becomes wider, not only the longitudinal current but also the transverse current increases; the longitudinal and transverse currents generate the co- and cross-polarized radiation, respectively. To reduce the transverse current flows on the large-width radiating element, the width of the connecting part with the feeding line in the radiating element is narrowed. Additionally, the transverse current can be further reduced by adding a notch on the top of the radiating element. These two deformed radiating elements are proposed and used to design 18-element comb-line array antennas according to the array design procedure based on the radiation conductance. The array antennas were designed for the SLL of -20 dB at 79 GHz. The prototypes are fabricated and the antenna performance was measured. From the measurement results, the comb-line antenna composed only of the conventional stub-shaped elements shows the SLL of about -16.58 dB, whereas the array antenna using the proposed elements has the SLL of -19.4 dB. This paper demonstrates the feasibility of the proposed elements for low SLL, through analysis and measurement.

We propose the integration of the resonant coil for wireless power transfer (WPT) and the implantable antenna for physiological signal transfer. The integration allows for a compact biomedical implantable system such as electrocardiogram (ECG) recorder and pacemaker. While the resonant coils resonate at the frequency of 13.56 MHz for the WPT, the implantable antenna works in the medical implant communications service (MICS) band of 402–405 MHz for wireless communications. They share the narrow substrate area of a bar-type shape; the coil has the current path on the outer part of the substrate and the meandered planar inverted-F antenna (PIFA) occupies the inside of the coil. To verify the potentials of the proposed structure, a prototype is fabricated and testedin vitro. The power transfer efficiency (PTE) of about 20% is obtained at a distance of 15 mm and the antenna gain of roughly −40 dBi is achieved.