【摘要】：移相器是一種能夠?qū)﹄姶挪ǖ南辔贿M(jìn)行調(diào)整的微波器件,廣泛地應(yīng)用于雷達(dá)系統(tǒng)、微波通信系統(tǒng)和測量系統(tǒng)等軍用以及民用工程系統(tǒng)中。移相器有多種類型,其中鐵氧體移相器由于具有插入損耗小、功率容量高、工藝成熟以及價格低廉等特點(diǎn)而得到廣泛的應(yīng)用。本文研究了適用于Ka波段鐵氧體移相器的LiZn鐵氧體,并以此為磁心材料,研究設(shè)計(jì)了Ka波段用背脊式波導(dǎo)非互易鎖式鐵氧體移相器。首先,研制了具有高飽和磁化強(qiáng)度(Bs)和高剩余磁化強(qiáng)度(Br)、高矩形比(Br/Bs)和低矯頑力(Hc)等特性的LiZn鐵氧體。主要研究了添加劑Bi2O3和燒結(jié)溫度對LiZn鐵氧體性能的影響,并得知Bi2O3添加量為1wt%以及燒結(jié)溫度為980℃時,能較好地兼顧LiZn鐵氧體材料的矯頑力、飽和磁化強(qiáng)度、剩余磁化強(qiáng)度和矩形比的目標(biāo)要求。研制了Bs420mT,Br370mT,Hc120A·m-1和Br/Bs0.85的LiZn鐵氧體旋磁材料。其次,采用電磁仿真軟件Ansoft HFSS 12.0對移相器在33.5~34.5GHz頻率范圍內(nèi)進(jìn)行電磁仿真設(shè)計(jì),研究了移相器結(jié)構(gòu)對移相器性能的影響。結(jié)果表明:增大鐵氧體矩形環(huán)的壁厚、使用高介電常的填充介質(zhì)和縮小鐵氧體磁心孔的寬度會提高鐵氧體移相器的差相移;另外,增大背脊波導(dǎo)的背脊高度,差相移也會增大,但會惡化移相器相移量的頻率響應(yīng)特性。優(yōu)化了移相器的結(jié)構(gòu)尺寸,仿真結(jié)果表明:在33.5~34.5GHz范圍內(nèi),鐵氧體矩形環(huán)為20mm時,移相器插入損耗絕對值小于0.91dB,電壓駐波比小于1.08,在34GHz處相移量達(dá)到276°。最后,研究了移相器的裝配技術(shù)與移相器驅(qū)動系統(tǒng),并利用矢量網(wǎng)絡(luò)分析儀對移相器實(shí)物進(jìn)行測試。測試結(jié)果表明,在室溫下,33.5~34.5GHz頻段內(nèi),長度為20mm的1號移相器,駐波比小于1.4,插入損耗絕對值小于1.05dB,在中心頻率點(diǎn)34GHz處的相移量為149°;長度為20mm的2號移相器,駐波比小于1.4,插入損耗絕對值小于1.6dB,在34GHz處的差相移為146°;由1號和2號移相器連接而成的3號雙節(jié)移相器,電壓駐波比小于1.5,插入損耗絕對值小于2.3dB,在34GHz處的相移量為293°。隨后分析了實(shí)測結(jié)果與仿真結(jié)果產(chǎn)生巨大差別的原因。
[Abstract]:Phase shifter is a kind of microwave device which can adjust the phase of electromagnetic wave. It is widely used in radar system, microwave communication system, measurement system and other military and civil engineering systems. There are many types of phase shifter, among which ferrite phase shifter has been widely used because of its low insertion loss, high power capacity, mature process and low price. In this paper, the LiZn ferrite suitable for Ka-band ferrite phase shifter is studied, and the back-ridge waveguide non-reciprocal lock ferrite phase shifter for Ka band is designed with the LiZn ferrite phase shifter as magnetic core material. Firstly, LiZn ferrites with high saturation magnetization (Bs), high residual magnetization (Br), high rectangular ratio (Br/Bs) and low coercive force (Hc) were prepared. The effects of additive Bi2O3 and sintering temperature on the properties of LiZn ferrite were studied. It was found that the coercive force and saturation magnetization of LiZn ferrite could be taken into account when the content of Bi2O3 was 1wt% and the sintering temperature was 980 鈩，

本文編號：2468064