The South China University of Technology

Yuanchun Li

Quan Xue

Disi Wu

Xin Fang

Qinchuang Chen

A dual-band filtering switch based on a single quad-mode dielectric resonator (DR) includes: a first printed circuit board (PCB) provided thereon with an input terminal; a second PCB provided thereon with an output terminal; a shielding shell arranged between the first and second PCBs and enclosing a shielding cavity together with the first and second PCBs; and a single quad-mode DR arranged in the shielding cavity. The first and second PCBs each include a feeding layer, a dielectric layer, and a ground layer that are stacked in sequence. The feeding layers of the first and second PCBs each include a microstrip line and a switching circuitry connected to the microstrip line, and the feeding layer is in contact with a surface of the DR to realize a switching function of the filtering switch. The proposed filtering switch feature low loss transmission and high selectivity with dual-band operation, miniaturization with the fewest resonators and friendly-integration, simultaneously.

Single quad-mode dielectric resonator having intersecting microstrip lines coupled to switching circuitry and selectively configured for dual-band transmission/isolation

The invention discloses a cavity-based dual-band filtering balun, which includes a first cavity resonator and a second cavity resonator which are connected by a metal plate, the first cavity resonator is provided with an input PCB board, a metal ground layer of the input PCB board is provided with an input through line, the other side of the input PCB board is provided with an input microstrip line, and the first cavity resonator is provided with an input slot corresponding to a position of the input through line; and two opposite outside surfaces of the second cavity resonator which are adjacent to the metal plate are each provided with an output PCB board, metal ground layers of the two output PCB boards are respectively provided with an output through line, the other sides of the two output PCB boards are each provided with an output microstrip line, and the second cavity resonator is provided with an output slot corresponding to a position of the output through line and communicated with the output through line. A main body of the dual-band filtering balun includes two cavity resonators, its structure is high in quality factor and low in insertion loss, and meanwhile, the requirement of two passbands is realized by using two fundamental modes of the cavity resonators, thus reducing a size of a circuit.

Cavity-based dual-band filtering balun

The invention discloses a LTCC wide stopband filtering balun based on discriminating coupling. The filtering balun includes a dielectric, and a first resonator, a second resonator, a first feeding line, a second feeding line, a third feeding line and a metal ground which are arranged inside the dielectric. The two resonators are both half-wavelength resonators distributed on different layers, and the layers are connected through metal through holes. the first feeding line is coupled with a specific area of the first resonator for performing feeding to suppress a second harmonic, and the second feeding line and the third feeding line are coupled with a specific area of the second resonator for performing feeding to suppress a third harmonic, thus realizing a wide stopband filtering performance. The second feeding line and the third feeding line are symmetrically arranged about a center of the second resonator, thus realizing a same-amplitude reverse-phase balun output characteristic. The LTCC wide stopband filtering balun based on discriminating coupling according to the invention can suppress the second harmonic and the third harmonic, and a LTCC multi-layer circuit technology used reduces a size of a filtering balun.

LTCC wide stopband filtering balun based on discriminating coupling

A wide bandpass filtering power amplifier using discriminating coupling is disclosed, which comprises a DC bias circuit, an input impedance matching circuit, a transistor and an output impedance matching circuit. The DC bias circuit is connected to the input impedance matching circuit which is further connected to the transistor, and the transistor is further connected to the output impedance matching circuit which comprises a tuning microstrip line and a bandpass filter. The complexity and the area of the impedance matching circuit in the power amplifier are effectively reduced. At the same time, the filtering PA has good frequency selectivity by using the discriminating coupling BPF. Meanwhile the work efficiency and bandwidth of the filtering power amplifier are effectively improved by taking both of the extended continuous mode theory and filter synthesis theory into account.

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Guangdong, China

Yuanchun Li