On The Active Phased Array Antenna Borne On Shiand Communication Antennas

The research works are based on scientific projects. This dissertation discusses thedesign of the shipborne active phased array antenna and the communication antenna. Inthe research on the shipborne active phased array antenna, the effect of the hull platformon the electrical characteristics of the shipborne active phased array antenna, and aneffective method of reducing the Radar Cross Section (RCS) is given based on theanalysis results. In the study of the communication antenna, the design of the originalantenna is improved. As to different purposes, the improved antennas are characterizedby wideband, high gain, beam scanning, and so on.The research works involved can be divided into two parts: the design anddevelopment of the shipborne active phased array antenna constitute the first part; thesecond part represents the design and development of communication antennasincluding the point-point communication antenna for flood control and calamityreducing, the helicopter search and rescue communication antenna, the ultra-wideband(UWB) wireless communication terminal antennas and the broadband high gainmissile-borne antenna array. The main research works and contributions of the authorare outlined as follows:1. In the study of the shipborne active phased array antenna, a novel antennaradiating element with a metal back cavity is introduced to realize beam control of theantenna radiating element and improvement of the isolation between subarrays. Theproposed antenna array has a scanning gain of greater than21.3dB and a beam scanningrange of-450~450in the azimuth plane. Second, the RCS of the antenna array is reduced.The RCS of the antenna array is effectively reduced from10000m2to100m2throughslanting installation. Third, the outside surface of the antenna is completely conformalwith the hull. For this, an embedded groove structure with parallelogram section in sidesof boats is proposed. The RCS of the array antenna is effectively improved and theantenna array is conformal with the carrier platform. Based on these studies, theprototypes of the antenna radiating element and subarray are fabricated and measured.The operating frequency of the proposed antenna is UHF band. The proposed antennaarray has a beam scanning range of-450~450and a scanning gain of greater than21.3dB.The RCS of the proposed antenna is50m2. These measured results show that theproposed antenna can satisfy the design requirements and it has been applied in the engineering.2. A circularly polarized substrate integrated waveguide (SIW) feeding ellipticdielectric resonant antenna with a single-slot coupling structure is proposed. In view ofthe design requirements of the point-to-point communication system for flood controland calamity reducing, the antenna should be broadband and circularly polarized. Thelatest SIW feeding method is used to design the circularly polarized elliptic dielectricresonant antenna with a single-slot feeding coupling structure. The integral design of theantenna is conducted with the simulating software HFSS. The design results show thatthe antenna has a gain of greater than18.5dB and an axial ratio of less than3.3dBwithin9.4GHz±350MHz. On the basis of design, the prototype of the antenna array isfabricated and measured. The measured results show that the proposed antenna achievesa gain of greater than18.2dB and an axial ratio of less than3dB, which can meet thedesign requirements of the communication system and has been applied in theengineering.3. Based on SIW, a new design method of the broadband frequency scanningmicrostrip antenna array with a simple feeding structure is proposed. In view of thedesign requirements of the helicopter search and rescue communication system, theantenna should have electric scanning radiation patterns. A broadband frequencyscanning microstrip antenna array is proposed with SIW feeding technology. Theprototype is fabricated on the simulation design basis. The measured results show thatthe proposed antenna array achieves a beam scanning range of-160~160in the azimuthplane and a scanning gain of greater than12.7dB ranging from8.5GHz to12GHz,which can satisfy the engineering requirements.4. A novel edge gradient miniature UWB printed antenna is proposed. Based on thenarrow slot resonant structure, the half-mode SIW resonant structure and the SIWresonant structure, three kinds of band-notched UWB antennas are proposed. Theseantennas are simulated with the simulating software HFSS. The prototypes arefabricated and measured. The measured results show that the proposed antennas havefrequency bands of greater than3octave band, indicating the broadband feature. Themaximum VSWR at the notched bands are11.7,9.8and28.9, respectively.5. A modified UWB radial waveguide power divider based on SIW is proposed,which has a relative bandwidth of62%, compared with that of the original (5.7%).These achievements are applied to the development of a missile-borne directionalantenna with the direction of maximum radiation pointing at the missile tail. The integral design of the4-element missile-borne microstrip antenna array with theproposed SIW radial waveguide power divider is conducted with Ansoft HFSS. Theprototype is fabricated and measured. The measured results show that the proposedantenna array achieves a gain of greater than11dB and beam coverage of greater than310, which can satisfy the requirements of the missile-borne communication system andhas been applied in the engineering.