Coupled-line Power Divider Research Articles

Wide Band Folded Coupled Line Power Divider Using Metamaterial for Mobile Application

Wide Band Folded Coupled Line Power Divider Using Metamaterial for Mobile Application

광대역 임의의 위상차를 갖는 대역통과 결합 선로 전력분배기

광대역 임의의 위상차를 갖는 대역통과 결합 선로 전력분배기

Analysis and Design of Wideband 90° Microstrip Hybrid Coupler

A wideband 90° microstrip hybrid coupler with a bandwidth of 84.3% is proposed. The hybrid coupler consists of a two-section coupled-line power divider and a 90° phase shifter. The two-section coupled-line is of natural broadband characteristics, and not only performs the role of impedance matching, but also makes the total circuit compact. The phase shifter employs a pair of open- and short-circuit stubs inserted into the reference transmission line to compensate the phase variation in proportion to the operating frequency for the conventional transmission line. Thus, the phase shifter possesses wideband performance on impedance matching as well as phase shifting. To prove the design methodology, a wideband 90° hybrid coupler operating at 3 GHz is designed and fabricated. In the case of −15 dB reflection coefficient for all ports of the coupler, the output maximum amplitude unbalance is less than 1 dB, the phase variation is less than 5 degree, and the port isolation is better than 18 dB.

Excitation of a broadband circularly polarized and arrow-shaped dipole antenna with high gain by an improved hybrid coupler

This paper proposed a novel wideband, circularly polarized crossed dipole antenna with high gain that utilizes an improved feeding work. The hybrid coupler exhibits both compact circuit configuration and a wide bandwidth (S11 ≤ −15 dB) of over 60% given a power distribution of −3.1 dB using a broadband coupled-line power divider and a 90° phase shifter with an impedance-open-stub. A phase deviation of 90° ± 5° was also observed over wideband. When excited by the wideband feed network, the circularly polarized crossed dipole antenna achieves an impedance bandwidth of 66.7% given S11 ≤ −15 dB and a 3 dB axial ratio bandwidth of 67%. Furthermore, the stable peak gain increased from 9 to 10.9 dBi between 1.07 and 1.7 GHz when a cylindrical cavity was connected to the ground. Moreover, the cross-polarization ratio in the wideband exceeds 25 dB. The simulated results of this study agree with the measured ones.

A Novel Harmonics-Suppression Coupled-Line Gysel Power Divider for Complex Terminated Impedances

A novel symmetrical coupled-line circuit structure is proposed to design a kind of harmonics-suppression coupled-line Gysel power divider that has the advantages of a compact structure and complex source to load-terminated impedances. It consists of four pairs of coupled lines, three pairs of transmission line stubs, and two grounded isolation resistors. Based on the traditional even- and odd-mode technique, closed-form mathematical equations for both circuit electrical parameters and scattering parameters are obtained. For demonstration purposes, two typical simulation examples with realized physical dimensions in microstrip technology are presented, indicating equal power division, good return loss, perfect isolation, and harmonics suppression on three different frequencies or wide operating frequency band. Finally, two practical microstrip coupled-line Gysel power dividers are designed and fabricated to operate at approximately 1 GHz. Good agreement between the simulated and measured results verify the design.

A novel wide-band hybrid coupler using coupled-line power divider and improved coupled-line phase shifter

A novel hybrid coupler aiming for wide-band applications is proposed in this paper. This hybrid coupler consists of a broadband Wilkinson coupled-line power divider and an improved wide-band coupled-line phase shifter. Taking advantage of the coupled-line section, the power divider achieves both compact circuit configuration and wide-band performance. In lieu of patterned ground plane and lumped capacitors, the coupled-line phase shifter can be constructed on a single-layer printed circuit board for wide-band operation. For this proposed phase shifter, the scattering parameters (S-parameters) expressions are derived and the optimal structural design parameters for achieving zero reflection coefficients are highlighted. After carefully choosing the circuit parameters, a new wide-band hybrid is constructed by combining a power divider and the proposed phase shifter. To verify against the theoretical calculation in terms of S parameters and phase information, a hybrid operating at 3 GHz is designed, simulated, and fabricated through microstrip technology. Close agreement is obtained between simulation and measurement results.

A GENERALIZED COUPLED-LINE DUAL-BAND WILKINSON POWER DIVIDER WITH EXTENDED PORTS

A generalized two-way coupled-line power divider with extended ports for dual band is proposed in this paper. The power divider is composed of two section coupled-lines, one conventional transmission line, and an isolation resistor, and employs extension of a transmission line or coupled-line at each port. The design equations are obtained based on even- and odd-mode analysis, and analytical ideal closed-form scattering parameter expressions derived. Because the traditional ring structure is a special case of coupled line, four cases of this generalized power divider are discussed and compared. In addition, the six power dividers simulated results of three special cases are shown. Finally, three fabricated power dividers measurements are used to certify this proposed structure and corresponding design parameters.

Flexible Design of a Compact Coupled-Line Power Divider

Studies indicate that the size reduction of a conventional coupled-line power divider can be implemented with the introduction of reactive elements at the output ends of the pair of coupled-line sections. A theoretical analysis of such a kind of power dividers is performed, and simple design equations are presented in this paper. By choosing the electrical length of the coupled-line section as 30°, a very compact coupled-line power divider is demonstrated. Centered at 1.5 GHz, a validation circuit is optimally designed, built and experimentally verified. Measurements, which match the predictions, confirm the proposed compact divider topology and design procedures.

Coupled line power divider with compact size and bandpass response

The design and implementation of a new power divider using coupled microstrip lines are presented. The proposed divider can be considered as an integration of a single-stage coupled line bandpass filter and a conventional Wilkinson divider. The area of the divider layout is compact owing to the small width and spacing of the coupled lines. Two-way and three-way equal power dividers are designed for the bandwidth between 3–5 GHz having a measured power division of −3.2 and −5 dB, respectively.