通信專業(yè)畢業(yè)設(shè)計外文翻譯--新的雙頻雙極化開槽微帶天線的設(shè)計方法

1、<p>　　A Novel Method for Designing Dual-Frequency Slot Patch Antennas with Two Polarizations</p><p>　　WU Di1, OH ISH I BA SH I H idekazu2, SEO Kazuyuk i2, I NA GA K IN aok i3</p><p>　　(1. D

2、epartment of Communication Engineering , Shang hai University , Shang hai 200072, China;</p><p>　　2. Kojima R &D Center, Kojima Press Industrial Co Ltd , Aichi 470—0207, Japan;</p><p>　　3. N

3、agoya Institute of Technology, Nagoya 466—8555, Japan)</p><p>　　Abstract: This paper presents a new method for designing a dual-frequency patch antenna with circular and linear polarizations. Dual-frequency

4、operations are behaved by etching two narrow slots close to the radiating edges of a rectangular patch. The circular polarization at the lower resonant frequency of the dual-frequency antenna can be achieved by setting a

5、 perturbation segment at an appropriate location in the patch element, and placing the feed point on the diagonal axis. Several experimen</p><p>　　CLC number：TN821.1 Document code： A</p><p

6、>　　Key words: dual-frequency; slot patch antennas; linear polarization; circular polarization</p><p>　　In radar and communication systems, dual-frequency operations are often required. Specially, in mode

7、rn mobile global position system (GPS), it will be desirable that one of two frequencies is the circular polarization. Planar antenna has been investigated for multi-frequency very well since it is advantageous in low co

8、st, low weight and conform ability. Early dual-frequency planar antenna is multilayered stacked-patch structure, and the radiating element is used to be circular[1], annular[2], r</p><p>　　In this paper, we

9、present a design method of a dual-frequency antenna with circular and linear polarizations based on the conventional investigation for the dual-frequency linear polarization antenna[5～7], Two resonant frequencies are det

10、ermined by adjusting the size of the patch element and the slot, as well as the location of the slot in the element. The key to obtain a circular polarization for an antenna is to satisfy the condition for exciting circu

11、lar polarization, ie， the circular polariz</p><p>　　Configuration of conventional dual-frequency patch antenna</p><p>　　Figure 1 shows a configuration of a conventional dual-frequency antenna wi

12、th linear polarization. Two resonant frequencies are behaved by etching two slots close and parallel to the radiating edges, and the lower resonant frequency is determined by the outline size of the patch element, while

13、the upper resonant frequency is determined by the size and the position of the two slots in the patch element. Because the slots are closely located to the radiating edges, a minor perturbation of the TM10 </p>&l

14、t;p>　　Our object in this investigation is to obtain a dual-frequency antenna with both polarization in which the lower frequency is with a circular polarization and the upper frequency is with a linear polarization. F

15、or a square patch antenna with area of S fed by one port, a way to excite a circular polarization is to extend the length of two parallel subtends of the patch element in order to set a perturbation segment ⊿s, and place

16、 the feeding point on the diagonal axis. When an appropriate perturba</p><p>　　Fig 1 Configuration of conventional dual-frequency antenna</p><p>　　2　Designing for dual-frequency slot patch anten

17、nas with two polarizations</p><p>　　In a conventional investigation for dual-frequency with linear polarization[5～ 7 ], to ensure a</p><p>　　good radiation efficiency at both frequencies, the as

18、pect ratio between the two sides of the patch is</p><p>　　taken in the range (1)</p><p>　　and the lower frequency is determined by (2)</p

19、><p>　　where c is the velocity of light in free space，is the effective permittivity given by </p><p><b>　　(3)</b></p><p>　　and

20、 (4)</p><p><b>　　(5)</b></p><p>　　here (6)</p><p>　　and the upper frequency is determined by (7)</p><p>　　In above expression

21、, the parameters of W, L, t, w, d, l are referred to Fig 2, and the is the dielectric constant of the substrate. However, in this study, in order to obtain a circular polarization at the lower resonant frequency, the a

22、spect ratio of the outline size of the patch will be changed so that the mentioned formulas above will not be completely satisfied.</p><p>　　Fig 2 Configuration of dual-frequency</p><p>　　We pre

23、sent a design method for dual-frequency slot patch antenna with two polarization as follows.</p><p>　　Step 1 Design a square patch antenna with the desirable lower frequency f10 by using a conventional meth

24、od.</p><p>　　Step 2 Etch two slots close and parallel to the radiating to behave the dual-frequencies operation by using Eq (7). However the lower resonant frequency f10 will change, since the slots modify

25、the current distribution of the TM10.</p><p>　　Step 3 Adjust the size of the antenna element to obtain the desired lower resonant frequency.</p><p>　　Step 4 Adjust the length and the width of

26、the slots to obtain the upper resonant frequency f30.</p><p>　　Step 5 Set perturbation segment and place the feed point on the diagonal axis of the antenna to obtain the circular polarization at the lower r

27、esonant frequency f10.</p><p>　　Experimental results and discussion</p><p>　　We experimentally designed a dual-frequency patch antenna with two polarizations. Figure 2 shows the configuration of

28、 the antenna, and the specifications are listed in Table 1. In this configuration of the antenna, we extended the L edge of the patch antenna to set the perturbation segment, and placed the feed point on the diagonal axi

29、s to achieve the circular polarization.</p><p>　　Table 1 Specifications of a dual-frequency patch antenna with two polarization</p><p>　　Figure 3 shows a measured reflection loss of a designed d

30、ual-frequency antenna fed by 50? coaxial probe. From this figure, it can be observed that two resonant frequencies are achieves at desired frequencies 1.575GHz and 2.50GHz, which will be employed to mobile global positio

31、n system(GPS) and vehicle information & communication system (VICS), and a good simultaneous impedance matching was obtained for reflection loss values -17dB at 1.575GHz and-27dB at 2.5GHz.</p><p>　　Fig

32、3 Frequency characteristics of reflection loss</p><p>　　Figure 4 shows the axial ratio variation with the frequency for this designed antenna. It is seen that the best value of the axial ratio is about 1dB a

33、t 1.575GHz.</p><p>　　Fig 4 Frequency characteristics of axial ratio</p><p>　　Figure 5 shows the measured impedance characteristics of the antenna in correspondence with Fig 3. It demonstrated th

34、at a perturbation is set for circular polarization at lower frequency 1.575GHz.</p><p>　　Fig 5 Frequency characteristics of input impedance</p><p>　　Figure 6 shows the radiation pattern of the c

35、ircular polarization of the designed antenna at the lower resonant frequency 1.575GHz. In this figure, we used the unit [dBic] for gain, which can be calculated as follows where, Gmax[dBi] denotes the measured maximum g

36、ain in [dBi], AR is the measured axial ratio. A gain of 3.7 [dBic] was found for patch antenna with circular polarization at 1.575 GHz.</p><p>　　Fig 6 Radiation pattern of circular polarization</p>&l

37、t;p>　　Finally, the radiation pattern of the linear polarization at the upper frequency 2.5GHz is shown in Fig 7. This is the perturbed TM30 mode, however, because the two slots exist in the patch, the shape of the rad

38、iation pattern of the perturbed TM30 mode becomes similar to that of TM10 mode. A gain of 5[dBi] was obtained for patch antenna with linear polarization at 2.5GHz.</p><p>　　Fig 7 Radiation pattern of linear

39、polarization</p><p>　　Concluding remarks</p><p>　　A novel design method for a dual-frequency patch antenna with both circular and linear polarization is presented in this paper. Two resonant fre

40、quencies are behaved by etching two slots close to the radiating edges in the rectangular patch, and the circular polarization at the lower resonant frequency is achieved by setting a perturbation segment in the patch el

41、ement, and by placing the feed point on the diagonal axis. A dual-frequency antenna with both polarizations, which will be used to GPS a</p><p>　　References :</p><p>　　[1]　Long S A , Walton M D.

42、 A dual-frequency stacked circular-disc antenna [J]. IEEE Trans Antennas Propagat, 1979, A P 27: 270 273.</p><p>　　[2]　Dahele J S, L ee K F, Wong D P. Dual frequency tacked annular-ring microstrip antenna [J

43、] . IEEE Trans, 1987, A P 35 (11) : 1281 1285 .</p><p>　　[3]　Wang J , Fralich R, W u C, et al . Multifunctional aperture coupled stack antenna [J ] . Electron L et t,1990, 26 (25) : 2067 2068 .</p>&l

44、t;p>　　[4]　M irschekar-syankalD, Hassani H R. Characteristics of stacked rectangular and triangular patch antennas for dual band application [A] . IEE 8th ICA P [C] .1993 . Edinburgh.</p><p>　　[5]　Maci S,

45、Bffi Gentili G, Avitabile G. Single2layer</p><p>　　dual2f requency patch antenna [J] . Electronics L etters, 1993, 29 (16) : 1441 1443 .</p><p>　　[6]　Maci S, Biffi Gentili G, Piazzesi P, et al .

46、 Dual-band Slot-loaded patch antenna [J]. IEEE Proceedings H,1995, 142 (3) : 225 232 .</p><p>　　[7]　Maci S, Bffi Gentili G. Dual-frequency patch antennas[J ] . IEEE Antennas and Propagation Magazine,1997, 39

47、 (6) : 13 20</p><p>　　新的雙頻雙極化開槽微帶天線的設(shè)計方法</p><p>　　吳迪，大石橋秀和，漱尾和之，蹈垣直樹</p><p>　?。?.上海大學(xué) 通信學(xué)院，上海20072； 2.小島總合研究所，愛知縣 470-0207，日本；</p><p>　　名古屋工業(yè)大學(xué)，名古屋市 466-8555， 日本）</p

48、><p>　　摘 要：提出了一種同時具有圓極化和線極化的雙頻新型開槽微帶天線的設(shè)計方法。天線雙頻工作是通過分別在靠近方形微帶天線的兩個輻射邊處各開一個平行的窄槽來實現(xiàn)的。在較低的諧振頻率處圓極化的可以通過在天線輻射單元上適當(dāng)?shù)卦O(shè)置攝動元素，并將饋電點移到輻射單元的對角線上。一個設(shè)計天線的測試結(jié)果給出了該天線在兩個諧振頻率上具有很好的圓極化和線極化的天線性能。</p><p>　　關(guān)鍵詞：雙頻；

49、開槽微帶天線；線性極化；圓極化</p><p>　　在雷達和通信系統(tǒng)中，經(jīng)常需要雙頻工作。特別是在現(xiàn)代的移動全球定位系統(tǒng)中，通常要求雙頻之一為圓極化。因為平面天線在低成本、重量輕和穩(wěn)定性方面的優(yōu)點，已經(jīng)被廣泛研究并較好的應(yīng)用于多頻帶系統(tǒng)中。早期的雙頻平面天線是多層棧式貼片結(jié)構(gòu)，它的輻射單元習(xí)慣上為圓形、環(huán)形、矩形和三角形。最近，提出了一種雙頻天線，這種天線的結(jié)構(gòu)是單層貼片，且有兩個槽靠近輻射邊緣，并且在兩個諧振頻

50、率上既實現(xiàn)阻抗匹配又具有好的增益性能。然而，常規(guī)的研究僅僅針對線性極化的天線，擁有圓極化的雙頻天線卻還沒有被實現(xiàn)。</p><p>　　本文中，在雙頻線極化天線傳統(tǒng)研究的基礎(chǔ)上，我們提出一種設(shè)計雙頻天線的方法，可設(shè)計出同時具有圓極化和線性極化特性的雙頻天線。兩個諧振頻率取決于調(diào)節(jié)貼片單元、槽的大小以、及槽在天線單元上的位置。一個天線獲得圓形極化的關(guān)鍵是滿足激勵圓形極化的條件，例如通過設(shè)置攝動元素⊿在貼片單元合適的

51、位置上，并將饋點設(shè)置于對角軸線上，這樣圓極化就可以被激勵。我們已經(jīng)用實驗的方法在高低頻率上獲得了圓極化和線極化，并且將會展示一些關(guān)于天線輸入端反射損失和輻射形式的實驗性結(jié)果。</p><p>　　傳統(tǒng)雙頻微帶貼片天線的結(jié)構(gòu)</p><p>　　圖1顯示了傳統(tǒng)線極化雙頻天線的結(jié)構(gòu)。通過在輻射邊緣蝕刻兩個緊密平行的槽，兩個諧振頻率就被表現(xiàn)了出來，并且較低的諧振頻率取決于貼片單元輪廓的大小，而較

52、高的諧振頻率取決于在貼片單元內(nèi)的兩個槽的大小和位置。因為兩個槽設(shè)計在輻射邊緣很近，所以在TM10模式下，應(yīng)該得到較小的攝動單元。對于無攝動單元的TM30模式來說，由于兩個槽位于對電流很重要的位置，所以電流將會發(fā)生很大的變化，而且將會得到一個與TM10相似的有干擾的TM30輻射圖。</p><p>　　我們的研究目的是獲得一個具有圓極化和線極化的雙頻微帶天線，這個天線具有如下特點：對于低頻來說是圓極化的，對于高頻來

53、說是線極化的。對于一個端口反饋面積為S的正方形貼片天線來說，一種激勵圓極化的方法就是：延長貼片單元平行邊的長度，設(shè)置一個攝動單元⊿s，并且將饋點設(shè)置在對角線上。當(dāng)選擇了一個合適的攝動單元時，將會獲得一個具有很好軸比的圓極化天線。</p><p>　　圖1 傳統(tǒng)雙頻天線的結(jié)構(gòu)</p><p>　　雙頻雙極化開槽貼片天線的設(shè)計</p><p>　　在雙頻線極化天線的傳統(tǒng)

54、研究中，為確保在雙頻上都具有好的輻射效率，貼片兩邊的縱橫比取值范圍是 （1）</p><p>　　并且低頻取決于 （2）</p><p>　　其中c為自由空間的光速，為有效的介電常數(shù)，通常</p><p><b>　　（3）</b></p>

55、<p><b>　?。?）</b></p><p><b>　?。?）</b></p><p>　　這里 （6）</p><p>　　高頻取決于 （7）</p><p>　　上述表達式中，參數(shù)W，L，t，

56、w，d，l參閱圖2，是基底的介電常數(shù)。然而，在本文研究中，為在低頻端獲得一個圓極化，貼片輪廓的縱橫比將會改變，因此，上述公式將不會完全得到滿足。</p><p>　　圖2 雙頻天線的結(jié)構(gòu)</p><p>　　我們提出了一種雙頻開槽雙極化天線的設(shè)計方法，如下所述：</p><p>　　第一步 用傳統(tǒng)方法設(shè)計符合要求的低頻的方形貼片天線。</p><

57、p>　　第二步 應(yīng)用方程（7），刻蝕兩個與輻射邊緣很近的平行槽來實現(xiàn)雙頻工作。然而，由于兩槽改變了TM10的電流分布，較低的諧振頻率f10將會改變。</p><p>　　第三步 校正天線單元的大小來獲得所想要的低頻。</p><p>　　第四步 校正兩槽的長寬來獲得較高的諧振頻率f30。</p><p>　　第五步 設(shè)置天線的攝動單元和饋點來獲得在低諧振頻率下

58、的圓極化。</p><p><b>　　實驗結(jié)果與討論</b></p><p>　　我們用實驗的方法設(shè)計了一個雙頻雙極化貼片天線。圖2展示了天線的結(jié)構(gòu)，天線的詳細(xì)說明如表1所示。在這個天線結(jié)構(gòu)中，我們延長貼片天線的L邊來來調(diào)節(jié)攝動元素，而將饋點設(shè)置在對角線上以便獲得圓極化特性。</p><p>　　表1 具有雙極化的雙皮貼片天線的詳細(xì)說明<

59、;/p><p>　　圖3顯示了測量到的所設(shè)計雙頻天線的反射損失，天線是由50?同軸電纜反饋的。由這幅圖可見，兩個諧振頻率均在所需的1.575GHz和2.50GHz兩個頻點附近，這兩個頻率將被應(yīng)用于GPS和VICS，并同時實現(xiàn)了較好的阻抗匹配：在1.575GHz附近的反射損失值為-17dB，在2.5GHz附近的反射損失值為-27dB。</p><p>　　圖3 反射損失的頻率特征</p&g

60、t;<p>　　圖4顯示了這個天線的軸比隨頻率變化而變化的關(guān)系?？梢钥闯鲈?.575GHz時的最佳軸比為1dB。</p><p>　　圖4 軸比的頻率特性</p><p>　　與圖3相比，圖5顯示了測量到的天線阻抗特性。這說明在低頻1.575GHz出為實現(xiàn)圓極化而留有攝動余量。</p><p>　　圖5 輸入阻抗的頻率特性</p><

61、;p>　　圖6顯示了在較低諧振頻率1.575GHz上設(shè)計的圓極化天線的輻射圖。圖中，我們使用單位dBic來表示增益大小，dBic可以通過下式計算得到：，其中Gmax[dBi]表示所測量的最大增益是,AR是測量的軸比。1.575GHz圓極化貼片天線的增益可以達到3.7[dBi]。</p><p>　　圖6 圓極化的輻射圖</p><p>　　最后，高端頻率2.5GHz附近線極化的輻射模

62、式圖如圖7所示。這屬于攝動的TM30模式，然而，由于貼片上存在兩個槽，攝動TM30模式的形狀變得和TM10模式很相似。在2.5GHz附近線極化貼片天線的增益可以達到5[dBi]。</p><p>　　圖7 線極化的輻射圖</p><p><b>　　結(jié)束語</b></p><p>　　本文中，我們提出了一種設(shè)計同時擁有圓極化和線極化特性的雙頻貼

63、片天線的方法。通過在靠近方形微帶天線兩個輻射邊處各開一個平行的窄槽得到兩個諧振頻率，在較低的諧振頻率處圓極化特性可以通過在天線輻射單元上適當(dāng)設(shè)置攝動元素，并將饋電點移到輻射單元的對角線上。采用上述方法設(shè)計了一個雙頻雙極化天線，這種天線將被應(yīng)用于GPS和VICS中。測量結(jié)果表明，天線有兩個諧振頻率，在低頻端1.575GHz時，圓極化的軸比可以達到1[dB]，增益可以達到3.7[dBic]；在高頻端2.5GHz時，線極化增益可以達到5[dB

64、i]。</p><p><b>　　參考文獻：</b></p><p>　　[1]　Long S A , Walton M D. A dual-frequency stacked circular-disc antenna [J]. IEEE Trans Antennas Propagat, 1979, A P 27: 270 273.</p><

65、p>　　[2]　Dahele J S, L ee K F, Wong D P. Dual frequency tacked annular-ring microstrip antenna [J] . IEEE Trans, 1987, A P 35 (11) : 1281 1285 .</p><p>　　[3]　Wang J , Fralich R, W u C, et al . Multifunctio

66、nal aperture coupled stack antenna [J ] . Electron L et t,1990, 26 (25) : 2067 2068 .</p><p>　　[4]　M irschekar-syankalD, Hassani H R. Characteristics of stacked rectangular and triangular patch antennas for

67、dual band application [A] . IEE 8th ICA P [C] .1993 . Edinburgh.</p><p>　　[5]　Maci S, Bffi Gentili G, Avitabile G. Single2layer</p><p>　　dual2f requency patch antenna [J] . Electronics L etters,

68、 1993, 29 (16) : 1441 1443 .</p><p>　　[6]　Maci S, Biffi Gentili G, Piazzesi P, et al . Dual-band Slot-loaded patch antenna [J]. IEEE Proceedings H,1995, 142 (3) : 225 232 .</p><p>　　[7]　Maci S,