In this paper, a balanced-to-balanced power divider is proposed, for the first time, with arbitrary power division, which can be regarded as the balanced form of a Gysel power divider. The constraint rules are provided for its mixed-mode and single-ended S-parameters. The six-port network is analyzed by simplifying it to two-port networks with other ports matched at the central frequency. Its critical characteristic impedances are then calculated analytically by our derived equations according to the desired differential-mode power division ratio. The maximum achievable power division ratio is 1:4.692 when the characteristic impedances are limited within the realizable range of 20-120 Ω. The impacts of several freely selected design parameters on the operating bandwidth are explored numerically. A prototype is realized by microstrip lines and lumped resistors with the power division ratio of 1:32. The balanced-to-balanced performances of unequal power division, low differential-mode insertion loss, good suppression of common-mode noises, and mode conventions have been demonstrated by the simulated and measured results of the balanced-to-balanced power divider prototype.

A Balanced-to-Balanced Power Divider With Arbitrary Power Division

In the conventional unequal-split Wilkinson power divider, poor selectivity for each transmission path is usually a problem. To surmount this obstacle, the parallel coupled-line bandpass filter structure is utilized as an impedance transformer as well as a band selector for each transmission path in the proposed unequal-split Wilkinson power dividers. However, the bandpass filters in the proposed dividers require careful design because they may not be functional under certain conditions. For example, the odd-order coupled-line filters are not appropriate for impedance transformers in the proposed unequal-split dividers and high-isolation requirement. Using the even-order coupled-line filter transformers, this study proposes two types of unequal-split Wilkinson power dividers. The first type of the proposed dividers arranges two filter transformers near two output ports, respectively, and is capable of achieving a highly remarkable isolation between the two output ports and a good band selection in each transmission path. Specifically, not only the operating band but also the lower and higher stopbands can achieve highly favorable isolation for this type of divider. By arranging the load impedance of each port properly, the second type of the proposed dividers, which has only one filter transformer to be shared by each transmission path near the input port, is also proposed to provide effective isolation between two output ports and favorable selectivity in each transmission path.

Unequal Wilkinson Power Dividers With Favorable Selectivity and High-Isolation Using Coupled-Line Filter Transformers

This paper presents dual-band equal/unequal Wilkinson power dividers based on a coupled-line section with short-circuited stub (called as the \coupled-line section" for short), which consists of a pair of parallel coupled lines and a short-circuited stub. With the analyses of the phase shift and equivalent characteristic impedance, the coupled-line section is used to replace the quarter-wavelength branch line in the conventional equal/unequal Wilkinson power divider to obtain excellent dual-band operation. The closed-form equations and design procedures of dual-band Wilkinson power divider are given, where one degree of design freedom is obtained and design ∞exibility is shown. As two examples, a dual-band equal Wilkinson power divider with the frequency ratio of 1:8 : 1 and an unequal one with the high power dividing ratio of 7 : 1 and frequency ratio of 1:8 : 1 are designed, fabricated and measured. The measurements are in good agreement with the simulations. It is shown that the proposed power dividers have simple topologies, and can be easily fabricated with small frequency ratios and high power dividing ratios.

/pdf/dual-band-equal-unequal-wilkinson-power-dividers-based-on-39t299se5b.pdf

Dual-band equal/unequal wilkinson power dividers based on coupled-line section with short-circuited stub

In this paper, a wideband filtering power divider (PD) with ultra-wideband harmonic suppression and isolation is proposed. The dual coupled-line sections are embedded to the conventional quarter-wavelength transmission lines, which helps to extend the passband of the PD. With the introduction of the short-circuit stubs shunted at the output ports and the coupled lines with the open-circuit stubs, the ultra-wide stopband can be implemented more efficiently, thus resulting in five transmission zeros from 2 to 6 GHz. Furthermore, the improved isolation structure with series connected a resistor and a capacitor can be utilized to realize the ultra-wide isolation frequency band. Using a single resistor between two output ports, we have achieved an excellent in-band isolation. For demonstration, a wideband filtering PD operating at 1 GHz with a 20-dB bandwidth of 50% and an ultra-wide stopband better than 20 dB from 2 to 6 GHz is designed, fabricated, and measured. The measured results agree well with the anticipation.

Wideband Filtering Power Divider With Ultra-Wideband Harmonic Suppression and Isolation

A novel Gysel power divider based on patch type structure is presented in this paper. The proposed power divider possesses broad bandwidth, small physical occupation and arbitrary power division. More than 30% bandwidth enhancement is achieved based on the i15dB input return loss criteria, while 55% size reduction is realized compared with conventional Gysel power divider. What's more, ∞at dividing is obtained in the design without using additional transmission line sections. Based on the novel structure, a design procedure of power dividers with unequal power division ratios is provided without using narrow microstrip line. To verify the design approach, the proposed power dividers with equal and unequal (2:1 and 4:1) power divisions at the centre frequency 1.5GHz are fabricated and measured. The results demonstrate that the design can fulfll our goals.

/pdf/compact-wideband-gysel-power-divider-with-arbitrary-power-29hyljv0xw.pdf

Compact wideband gysel power divider with arbitrary power division based on patch type structure

-A novel unequal Wilkinson power divider is presented. A coupled-line section with two shorts is proposed to realize the high characteristic impedance line, which cannot be implemented by conventional microstrip fabrication technique due to fabrication limitation. The proposed coupled-line structure is compatible with single layer integration and can be easily designed based on an even-odd mode analysis. As a design example, a 10:1 Wilkinson power divider at 2 GHz is fabricated and measured. The measured -10 dB bandwidth of S11 is about 16%, and the isolation S32 is better than -20 dB. The measured amplitude balance between output port 2 and port 3 is between -10.20 dB and -9.52 dB, and the corresponding phase difference is between 0deg and 4.6deg.

A 10:1 Unequal Wilkinson Power Divider Using Coupled Lines With Two Shorts

This paper presents a miniaturized branch-line coupler with suppression of wideband harmonics based on a unit of transmission-line section with triple-stub. This fundamental unit produces three transmission zeros and exhibits wide stopband response due to the triple stubs. It is used to replace a quarter-wavelength line in conventional branch-line coupler, leading to size reduction and wideband harmonics suppression. The closed-form equations are given for the coupler design. As an example, a branch-line coupler operating at 1.0GHz is designed, fabricated and measured. Measurements agree well with simulations, and show that the proposed branch-line coupler occupies 56% size of a conventional one and achieves wideband harmonics suppression (better than 17dB) from 1.8GHz to 6.4GHz. The 2nd, 3rd, 4th, 5th, and 6th harmonics are suppressed better than 34dB, 19dB, 30dB, 17dB, and 32dB, respectively. With the theoretical analyses and practical results, it is shown that the proposed one has the advantages of simple structure, convenient analysis and wideband harmonics suppression.

https://www.jpier.org/pierl/pierl17/20.10082602.pdf

A miniaturized branch-line coupler with wideband harmonics suppression

The invention discloses a microstrip slot coupling fed three-frequency dielectric resonant antenna. A dielectric resonant cavity is made of a high-dielectric-constant material and is formed on a dielectric floor; an air resonant cavity is embedded on the upper part in the center of the inside of the dielectric resonant cavity and is filled with air serving as a dielectric; metal patches are placed in the centers at the upper ends of the dielectric resonant cavity and the air resonant cavity; a microstrip coupling slot feed source comprises a slot and a microstrip; the slot is formed in the dielectric floor; and the lower surface of the dielectric floor is provided with the microstrip and is vertically crossed with the slot. In the invention, three structures, namely the dielectric resonant cavity, the air resonant cavity and the metal patches, are integrated together to provide three different frequency points, so that the antenna has the characteristics of small size and wide frequency band, can be excellently applied to an antenna array and other aspects, namely various communication equipment and systems such as mobile terminals, wireless access points, base stations and the like, and can also be widely applied to some national defense tactical systems such as radars and the like.

Microstrip slot coupling fed triple-frequency dielectric resonant antenna

The invention discloses a three-frequency medium resonant antenna with a function of coaxial feed. A medium resonant cavity is the resonant cavity which is made from a high dielectric constant material, the medium resonant cavity is arranged on a ground potential surface, the upper part at the center in the medium resonant cavity is embedded with an air resonant cavity, a filling medium in the air resonant cavity is air, a metal paster is arranged at the center of the upper ends of the medium resonant cavity and the air resonant cavity, a coaxial feed source comprises a probe needle, a mediumlayer and an outer conductor, the probe needle penetrates through the ground potential surface from the lower part of the ground potential surface to enter into the medium resonant cavity, the mediumlayer is arranged between the ground potential surface and the probe needle, and the medium layer under the ground potential surface is externally provided with the outer conductor. The medium resonant cavity, the air resonant cavity and the metal paster are integrated with one another to offer three different frequency points, so that the three-frequency medium resonant antenna has the characteristics of being small in volume and wide in frequency band, thereby being capable of playing an important role in satellite communication and military electronic countermeasure uniquely.

Bo Li

Papers

A 10:1 Unequal Wilkinson Power Divider Using Coupled Lines With Two Shorts

Dual-band equal/unequal wilkinson power dividers based on coupled-line section with short-circuited stub

A miniaturized branch-line coupler with wideband harmonics suppression

Microstrip slot coupling fed triple-frequency dielectric resonant antenna

Three-frequency medium resonant antenna with function of coaxial feed