Abstract: In the present invention, a novel multi-port microwave circuit, also known as a multiple bi-directional circulator, is designed based upon the basis of the EBG characteristic of the meta-materials. Firstly, the concept of the traditional single-layered mushroom structure is extended with the suspending microstrip line to the multi-layered structure. In this way, the multi-layered structure can reveal multi-band EBG characteristic and achieve miniaturization. Moreover, we use three sets of proposed dual-band EBG circuit to be series-connected in a ring-type structure. By using proper impedance matching, the design of the multiple bi-directional circulator is accomplished. It combines the capabilities of the diplexer, the duplexer and the circulator. The triplex bi-directional circulator can integrate three kinds of communication systems with each other, which operates at frequencies comprising GSM 1800 MHz, WiFi 2.45 GHz, and WiMAX 3.5 GHz, respectively.

Abstract: A leaky-wave antenna capable of multi-plane scanning is provided. The leaky-wave antenna includes a substrate, a first antenna series, a second antenna series and a plurality of control units. The first antenna series intersects with the second antenna series to share a predetermined antenna unit among many antenna units. A part of the antenna units is connected in series to extend from a first and a second transmission lines of the predetermined antenna unit to compose the first antenna series, and the other antenna units are connected in series to extend from a third and a fourth transmission lines of the predetermined antenna unit to compose the second antenna series. The control units control the transmission paths between the first to the fourth transmission lines and the antenna units, and switch a leaky beam to different scanning planes, wherein the leaky beam scans with frequency variation through the antenna units.

Abstract: In the present invention, a novel multi-port microwave circuit, also known as a multiple bi-directional circulator, is designed based upon the basis of the EBG characteristic of the meta-materials. Firstly, the concept of the traditional single-layered mushroom structure is extended with the suspending microstrip line to the multi-layered structure. In this way, the multi-layered structure can reveal multi-band EBG characteristic and achieve miniaturization. Moreover, we use three sets of proposed dual-band EBG circuit to be series-connected in a ring-type structure. By using proper impedance matching, the design of the multiple bi-directional circulator is accomplished. It combines the capabilities of the diplexer, the duplexer and the circulator. The triplex bi-directional circulator can integrate three kinds of communication systems with each other, which operates at frequencies comprising GSM 1800 MHz, WiFi 2.45 GHz, and WiMAX 3.5 GHz, respectively.

Abstract: A leaky-wave antenna capable of multi-plane scanning is provided. The leaky-wave antenna includes a substrate, a first antenna series, a second antenna series and a plurality of control units. The first antenna series intersects with the second antenna series to share a predetermined antenna unit among many antenna units. A part of the antenna units is connected in series to extend from a first and a second transmission lines of the predetermined antenna unit to compose the first antenna series, and the other antenna units are connected in series to extend from a third and a fourth transmission lines of the predetermined antenna unit to compose the second antenna series. The control units control the transmission paths between the first to the fourth transmission lines and the antenna units, and switch a leaky beam to different scanning planes, wherein the leaky beam scans with frequency variation through the antenna units.