基片集成波导天线设计

The Research of Broadband Millimeter-Wave Vivaldi Array Antenna Using SIW Technique

Li Bin Dong Liang Zhao Jiao-cheng

(Xi’an Electronic Engineering Research Institute, Xi’an 710100)

Abstract-A compact millimeter wave Vivaldi antenna array printed on thick substrate and fed by a substrate integrated waveguide (SIW) structure was proposed in this paper. It consists of

a compact SIW binary divider, which has minimize significantly the feed structure insertion losses and achieve a broadband performance in millimeter wave range, and four-elements printed Vivaldi array. The whole antenna array was designed, fabricated, and thoroughly investigated. The whole antenna and feed net were designed, fabricated on single substrate, which takes the advantages of small size, low profile, low cost and high performance etc. The simulation results show that the design is effective and right.

I.I NTRODUCTION

The Vivaldi array antenna with broadband capability [1] plays a increasingly important position in radar, communication and electronic counter measures (ECM) fields[2,3], which the performance and design have been making an intensive study since 1980s’. With the development of planar integrated circuits, the planar Vivaldi array antenna which is light in weight, low in cost, and intergraded easily, has attracted considerable attention in antenna design filed. The planar Vivaldi array antenna has been based on structure of microstrip[4] or stripline[5], which have been restricted at relatively low frequencies for transmission loss or complex structure. For example, Yang et al.

[4] developed a Vivaldi array antenna to cover the 8~12GHz bandwidth, but it was based on the microstrip technology and demonstrated an high insertion loss (over 3.5 dB) for feeding network. Schaubert et al [5] has designed a Vivaldi array antenna with stripline-fed, which has a relatively low insertion loss, but its structure has become very complex.

Substrate integrated waveguide (SIW) technology has been proposed for many years [6][7]. Due to the advantages of this technology, such as low cost, high Q-factor, low insertion loss, easy to be integrated and high density layout, SIW is widely used in many areas, for example, planar slot antenna array [8], filter [9], diplexer, hybrid coupler[10], power splitter [11]and so on. The whole SIW structure is composed by metallized via array, so it can be realized accurately by PCB or LTCC technology and can be combined seamlessly with microstrip circuit, which is well suitable for millimeter-wave integrate system design and manufacture.

In this paper, a compact millimeter wave vivaldi antenna array with SIW feeding network was presented, which can achieve a broadband performance and offer several advantages over other counterparts such as relatively low insertion loss, good design tolerance and circuit size compactness at the millimeter wave (MMW) range. This antenna configuration can be easily adapted to millimeter wave applications with a conventional low-cost PCB fabrication process. The simulation results indicate that the antenna has good performance in all Ka-band.

II.D ESIGN OF BROADBAND MILLIMETER WAVE

VIVALDI ANTENNA ELEMENT

SIW structures are fabricated on printed circuit boards, which is similar as conventional metallic waveguide structure. The metal layer on surface can be viewed as upper and lower wall

of waveguide, and the two lines of metalized via can be viewed as two side-wall of waveguide. Utilizing SIW technology, a number of UWB antenna structure can be used [12].

The uniplanar tapered slot antenna also called Vivaldi antenna, which can be easily integrated with the rest of the circuits on a single substrate, has been implemented in many applications [4] since these years for its salient features such as narrow beam width, high element gain, wide bandwidth, and small transverse spacing between array elements. Therefore, it has been widely applied in the development of millimeter-wave integrated circuits and systems.

A novel SIW feeding architecture based on the scheme of Vivaldi antenna is proposed and demonstrated with excellent performances in millimeter-wave ka-band. The Vivaldi antenna element is generally easier to match over a