200921117 九、發明說明： 【發明所屬之技術領域】 本發明係有關一種電磁波測定裝置，適用在測定例如 由行動電話等所放射的電磁波。 【先前技術】 一般，就電磁波測定裝置而言，已知有將行動電話等 被測定物配置在小型之電波無響箱内，用以測定設置在該 被測定物之天線之輻射效率等（例如參照專利文獻丨、2)。 又在專利文獻1，揭示有為了提供小型且廉價的測定空 間’在電波無響箱内部設有在特定頻帶寬所使用之電波吸 收片。此時，電波吸收片在電磁波之測定頻帶寬具有電波 吸收特f生。因此匕’其構成係對應於行動電話之使用頻帶寬 :使用不同不同的電波吸收片。亦即，例如對於議觀Z 帶係使用纟700〜900MHZ具有電波吸收特性之電波吸收 片；對於UGHz帶係使用在具有電波吸收特 性之電波吸收片；對於19GHz帶係使用纟i 75〜2 ggHz具 有電波吸收特性之電波吸收片；對於25gHz㈣使用在 厶35〜2.65GHz具有電波吸收特性之電波吸收片。 又’在專利文獻2,揭示有在電波暗室内將被測定物盘 測定用天線配置成可移動之構成。此時，#由調整被测定 物與測定用天線之位置，即使由被測定物所放射之電磁波 有在電波暗室内反射時’仍可利用複數個反射波之干涉而 減少合成反射波的強度。 (專利文獻1)曰本特開平10_93286號公報 200921117 (專利文獻2)曰本特開平6-237090號公報 【發明内容】 然而’在專利文獻1之電磁波測定裝置，可測定之頻 T寬受到電波吸收片能吸收之帶域所侷限。因此，例如， 姆於可放射複數頻帶寬電磁波之頻帶寬較寬的行動電話用 2線進行特性評量時，必須備有電波吸收片不同之複數個 兒波無響箱，俾以其等之複數個電波無響箱進行測定。其 結果，測定時間較長，且因置放複數個電波無響箱而需要 較大空間。另一方面，在使用可吸收寬帶域之電磁波之電 坡吸收片時，由於電波吸收片較大而使電波無響箱亦趨於 大型化。 、 又，在專利文獻2之電磁波測定裝置，由於在各個測 ^時決定被測定物與測笔用&線的Μ，因此，必須在測 弋開始前求出被測定物與測定用天線的位置關係。因此， 在測定前之準備須耗上許多時間，而有作業效率低的問題。 本發明，係有鐘於上述習知技術的問題而提出者，其 2在於提供-種電磁波測定裝置，能使用小型之電波無 二箱’以對於放射出複數„電磁波的被測定物之特性進 行測定。 為解決上述問題，申*奎直# 4％ τ巧辱利範圍第1項之發明，係— 種電磁波測定裝置，具備： 電波無響箱，係在呈箱狀之金屬Μ體内部設有電波吸 被測定物’設㈣電波無響箱内作為測定對象者；及 200921117 /貝J疋用天線，係與該被測定物對向設在該電波無響箱 内，用以測定來自該被測定物的電磁波；其特徵在於： 該被測定物’可放射複數頻帶寬之電磁波； 該電波吸收體，在包含該被測定物所放射電磁波中i 個以上頻帶之特定頻帶寬’具有高吸收特性，而在包含該 被測定物所放射電磁波中其餘丨個以上頻帶之其他頻帶 寬’具有低吸收特性； 該電波無響相之金属筐體，具有彼此對向的2個對向 面； 當將由該被測定物所放射之電磁波在該2個對向面之 一方反射並射入測定用天線的第1反射路徑之長度設為 L1，由該被測定物所放射之電磁波在該2個對向面之另— 方反射並射入測定用天線的第2反射路徑之長度設為L2， 在該電波吸收體之吸收特性較低之其他頻帶寬所包含之i 個以上頻帶中最大頻率與最小頻率間之中心頻率的波長設 為又時，在使該第1、第2反射路徑之長度L1、L2的差△ L為0_25 λ以上0.5久以下範圍的位置，配置該測定用天線。 在申凊專利範圍第2項之發明中，該電波吸收體，在 該特定頻帶寬所包含之最低頻帶以上的高頻帶寬，具有高 吸收特性’在頻帶寬包含低於該特定頻帶寬的頻帶之作為 該其他頻帶寬的低頻帶寬，具有低吸收特性。 申請專利範圍第3項的發明中，該金屬筐體係形成為 四角形筒狀；該測定用天線及被測定物分別被配置於，在 該金屬筐體的軸方向上彼此分隔、且在四角形橫截面之對 200921117 角線上從中心偏離的位置。 申請專利範圍第4項的發明中’該電波吸收體，係使 用含碳之電波吸收材料而形成為金字塔形狀或錐狀。 申请專利範圍第5項的發明中，該測定用天線，在該 電波吸收體之吸收特性較低之電磁波的頻帶寬具無指向 性0 根據申請專利範圍第1項之發 备珂；龟砹吸收 之吸收特性較低之其他頻帶寬所包含之i個以上頻帶中， 將其最大頻率與最小頻率間之中心頻率的波長設為又時， 在使該第1、第2反射路徑之長度L1、L2的差^為〇25 又以上〇.5又以下範圍的位置，配置該測定用天線。因此， 即使是電波吸收體之吸收特性較低之電磁 内反射，在2個對向面所反射之2個反射波，會因第，目 2反射路徑之差AL而產生相位差，經彼此干涉而抿銷。直 =，即使對電波吸收體之吸收特性較低之電磁波，亦能 抑制反射波的影響’因而能增加可測定之頻率帶域。 於例如可放射複數頻帶電磁波之行動電 ==行評量時，亦可在單-之電波無響箱内 別疋所有頻帶之電磁波，盔 I塑箱來針.目卜 ，、，1如$知技術般使用複數電波 來心敎，可提高敎作㈣效率。又， ^電波吸收體之吸收特性往寬頻化發雷 波吸收體’可使電波無響箱小型化電 握電波吸收體之吸收特性較由於可事先掌 波之波長來決定測定用天線的位置。因皮此1根據該電磁 置因此，無須為了決定 200921117 測疋用天線的位置， 波之影響較少的位置 定效率。 而實際邊進行電磁波測定邊尋找反射 ，可簡化測定前的準備作業而提高測 根據申請專利範圍第2項之發明，電波吸收體在特定 頻帶寬所包含之最低頻帶以上的高頻帶寬，具有高吸收特 性，在頻帶寬包含低於特定頻帶寬的頻帶之作為其他頻帶 寬的低頻帶I： ’具有低吸收特性。因& ’在特定頻帶寬以 上之高頻電磁波，可使用電波吸收體予以吸收，以抑制反 射波的發生n面’頻率較特^頻率為低的電磁波， 無法以電波吸收體吸收，會在金屬筐體内反射。然而，由 於以在複數條反射路徑產生差AL之方式來配置測定用天 線，可使複數個反射波干涉而抵銷，而能抑制反射波的影 響。又，相較於使用電波吸收體以吸收低頻電磁波之情形， 可縮小電波吸收體，使電波無響箱小型化。 根據申請專利範圍第3項之發明，係將測定用天線及 被測疋物配置於，在金屬筐體之軸方向上彼此隔開且在四 角形橫截面之對角線上從中心偏離的位置，因此，相較於 將測定用天線及被測定物配置在橫截面之對角線上之中心 位置的情形，可在複數條反射路徑產生差AL，利用複數個 反射波之相互干涉而可抑制反射波的影響。 又’由於係將測定用天線及被測定物配置在四角形橫 截面之對角線上，因此，例如可藉由將橫截面形成為正方 形狀之方式，在橫截面隔著對角線而具有對稱性。因此， 在以測定用天線來接收被測定物放射之水平偏波及垂直偏 200921117 :，可…偏波取得大致相同的特性。 在权正空間的衰減量時，可藉著測定任—方之偏波特性， 而對於兩種偏波進行校正，而可提升敎的作聿效率。 根據申請專利範圍第4項之發明，電波㈣㈣❹ 含石厌之電波吸收材料而形成為金字塔形狀或錐形，因此， 當將突出於金屬筐體之電波吸收體之突出尺寸予以增大， 則可吸收低頻側的電磁波。此時，當電波吸收體的突出尺 寸變大’電波無響箱的整體形狀亦變大。相對於此，在本 發明，低頻側的電磁波，係利用使複數個反射波相互干涉 而能抑制其影響，因此，既能縮小電波吸收體之突出尺寸 亦能擴大可測定之頻帶寬。 根據申請專利範圍第5項之發明，測定用天線在電波 吸收體之吸收特性較低之頻帶寬具無指向性。在此，當測 定用天線具有指向性時，不會受到來自周圍之反射波的影 響，僅有直接從被測定物射入測定用天線之直接波會被接 收。然而’由於提高測定用天線之指向性而使測定用天線 趨於大型化，會有無法將測定用天線配置在小型電波無響 箱内。因此，為了配置在小型之電波無響箱内，在電波吸 收體之吸收特性較低之其他頻帶寬（例如低頻側之帶域），乃 使測定用天線具無指向性，除直接波外亦接收反射波β此 時’本發明，由於係使複數個反射波相互干涉，因此，即 使是藉由測定用天線來接收反射波之帶域，亦能抑制反射 波之影響，且測定來自被測定物之直接波的特性。 【實施方式】 10 200921117 以下參照附圖以詳述本發明之實施形態之電磁波測定 裝置。 在圖1至圖4中，電波無響箱i，係由使用厚為例如 1〜2mm左右之鋁板而形成為箱型之金屬筐體2，以及設置在 該金屬筐體2内部的電波吸收體3所構成。又，電波無響 箱！除了可遮斷來自外部的電磁波，亦可防止内部之電磁 波的反射。 在此之金屬笸體2之形成，例如係分別在寬度方向（χ 方向）、軸方向〇r方向）、高度方向（2方向）具有5〇〜i〇〇cm 左右的長度。又’金屬筐體2’具有位在軸方向兩側之前壁 面2A和後壁面2B、位在實声太a ; Vh, 饥隹見度方向兩侧之左壁面2c和右壁 面=、及位在高度方向兩側之頂面2E和底面2卜此時， 在刖、後之壁面2A、2B ’形成彼此對向之對向面。又，在 左、右之壁面2C、2D亦形成彼此對向之對向面，且，頂面 2E、底面2F亦形成彼此對向之對向面。 又，左、右之壁面2C、2D及頂面2E、底面I形成 為延者軸方向之四角形筒狀，且， 兴釉方向正交之橫截面 (xz +面）係形成為正方形 * ^ 0 A _ 耆在軸方向之兩端側係 i面2A與後壁面2B所封閉。 要將诒、1 入在右壁面2D，為了 要將後述之破測定& 5裝入金屬筐 方式安裝了門2G。 0而U可供開閉之 尺寸m吏用例如含碳之電波吸收材料，形成外突 的之金字塔形狀或錐形，朝著金屬· 又’電波吸收體3,係當被測定物5放射出複 200921117 數頻帶之電磁波時，在包含被測定物5所放射電磁波之i 個以上頻帶的特定頻帶寬，具有高吸收特性，而在包含被 測疋物5所放射電磁波中其餘1個以上頻帶的其他頻帶 寬’具有低吸收特性。具體而言，如圖6所示，所使用之 被測定物5，例如係可放射80〇mHz帶、900MHz帶、1.5GHz 帶、1.9GHz帶、2.5GHz帶、5GHz帶之複數頻帶電磁波的 行動電話時，電波吸收體3在包含1.5GHz帶〜5GHz帶之特 疋頻帶寬，具有高吸收特性，在包含剩餘之8〇〇MHz帶及 90〇Mhz帶之其他頻帶寬’則吸收特性變低。因此，在特定 頻帶寬所包含之最低頻帶（1.5GHz帶）以上的高頻帶寬 (1.5GHz帶〜5GHz帶），具有例如較—20dB為高的吸收特 性，在含有低於特定頻帶寬之頻帶（8〇〇MHz帶、9〇〇MHz帶） 之低頻帶寬’具有較一20dB為低之吸收特性。 雙轴定位器4，如圖2所示，係設置在電波無響箱 部之例如軸方向後壁面2；8側。又，雙轴定位器4具備由電 (； 動馬達等構成之方位角旋轉部4A’利用該方位角旋轉部 4A’繞著與高度方向平行之01轴而旋轉於方位角0方向。 又，在雙軸定位器4的上部，設有仰角旋轉部4B，該 仰角旋轉部4B係使用例如複數個齒輪等，繞著與軸方向（γ 方向）平行之02轴而旋轉於仰角0方向。 又’在仰角旋轉部4B安裝被測定物5。藉此，雙軸定 位器4使被測定物5以彼此正交之〇 1軸與〇2軸這2個轴 為中心旋轉’以決定被測定物5的方位角0及仰角0。 將被測定物5安裝在仰角旋轉部4B，如圖5所示，使 12 200921117 用雙軸定位器4繞著〇1軸與〇2軸這2個軸旋轉。又，被 測定物5係由例如行動電話、行動終端機等所構成，且具 有被測定天線5Α ’以作為用來測定輻射效率之測定對象。 此日可之被測疋天線5 A ’由例如鞭形天線（whip antenna)、内 裝之晶片式天線等所構成。又，被測定物5，可適用在能故 射例如 800MHz 帶、900MHz 帶、1.5GHz 帶 ' 1.9GHz 帶、 2-5GHz帶、5GHz帶等複數頻帶電磁波的行動電話等。再 者’被測定物5雖以能玫射5個頻帶之電磁波者為其示例， 但未必為能放射5個頻帶之電磁波者，只要能放射2個以 上頻帶之電磁波即已足夠。 測定用天線6如圖2至圖4所示，係設置在電波無響 相1内部之例如在軸方向上之前壁面2A側。又，將測定用 天線6安裝至天線支撐具7，與被測定物5在轴方向（γ方 向）隔開距離R〇而成對向配置狀態。在此之測定用天線6， 係以例如小型雙錐天線（bic〇nica〖 antenna)構成，可選擇性 測疋水平偏波與垂直偏波之任一方。此時，測定用天線6 係使用天線支撐具7來切換所測定的偏波。又，測定用天 線6在電波吸收體3之吸收特性較低的低頻帶寬（例如 800MHz帶、900MHz帶），具無指向性。又，測定用天線6 連接於後述之網路分析器8。 在此，被測定物5及測定用天線6，係分別位在四角形 鉍截面之對角線D_D上，且位在從中心〇往寬度方向偏離 5 1、往高度方向偏離5 2的位置。因此，被測定物5及測 疋用天線6，被配置在例如橫截面之左斜面的上侧位置，在 13 200921117 寬度方向（X方向），被配置在接近左壁面2C(相較於右壁面 2D)的位置；在高度方向（Z方向），被配置在接近頂面2E(相 較於底面2F)的位置。 此時，由被測定物5朝向測定用天線6之電磁波，其 一部分在左、右壁面2C、2D分別反射而產生2個反射波。 又，由於係將被測定物5及測定用天線6配置在從橫截面 之中心Ο偏離的位置，因此，由被測定物5所放射之電磁 波在左壁面2C反射並射入測定用天線6之左側反射路徑之 長度設為L11’且’由被測定物5所放射之電磁波在右壁面 2D反射並射入測定用天線6之右側反射路徑之長度設為 L12時，2個反射路徑之長度L11、L12並不相同。又，當 電波吸收體3之吸收特性較低之低頻帶寬所包含之頻帶（例 如800MHz帶及900MHz帶）之最小頻率（例如824MHz)與最 大頻率（例如960MHz)間之中心頻率（例如892MHz)的波長 設為λ時’被測定物5及測定用天線6係配置於，左、右 反射路徑之長度L11、L12之差△LU^Ll'lLll —L12|) 為0_25λ以上0.5λ以下範圍（0.25人$八1^1$0.5；1)的位 置。 同樣地，從被測定物5朝測定用天線6的電磁波，其 一部分在上、下之頂面2Ε、底面2F分別反射而產生2個反 射波。此時，由被測定物5所放射之電磁波在頂面2Ε反射 並射入測定用天線6之上側反射路徑之長度設為[2 1，且， 由被測定物5所放射之電磁波在底面2F反射並射入測定用 天線6之下侧反射路徑之長度設為L22時，2個反射路徑之 14 200921117 長度L21、L22並不相同。又，將被測定物5及測定用天線 6配置於，上、下反射路徑之長度L21、L22之差△乙2(八 為〇.25λ以上〇5又以下範圍（〇25u △ L2S 0.5 Λ )的位置。 又，被測定物5至後壁面2Β間之距離R1與於測定用 天線6至前壁面2A間之距離R2彼此不同。此時，從被測 定物5朝測定用天線6之電磁波，其一部分在前、後壁面 2A、2B分別反射而產生2個反射波。又，由於距離R1、 R2不同，當將從被測定物5放射之電磁波在前壁面2A反 射並射入測定用天線6之前側反射路徑之長度設為L3丨，從 被測定物5放射之電磁波在後壁面2B反射並射入測定用天 線6之後側反射路徑之長度設為L32時，2個反射路徑之長 度L3 1、L32並不相同。又，將被測定物5及測定用天線6 配置於，前、後反射路徑之長度L31、L32之差/\L3(ZiL3 = | L31 — L3 2| )為 〇·25λ 以上 〇.5λ 以下範圍（0.25；lgAL3 S 0 · 5凡）的位置〇 網路分析器8如圖2所示，構成用以測定被測定物5(被 測定天線5A)所放射之電磁場的電磁場測定器，其係經由高 頻線路8A而連接於被測定天線5 a，且經由高頻線路8B而 連接於測定用天線6。此時，高頻線路8A、8B之一端侧連 接於外部之網路分析器8 ’另一端側則經由設置在前壁面 2A之連接板9而插入電波無響箱1的内部。又，網路分析 器8係使用測定用天線6來接收由被測定天線5A所送來之 電磁波（高頻信號）。藉此，網路分析器8乃計算出供應至被 15 200921117 6之接收電力之比 行列的參數S21。 測定天線5A之電力與來自測定用天線 率’測定出與空間之損失程度相當之s 本實施形態之電磁波測定裝置具備上述構成，其次， 說明使用該電磁波測定裝置之天線特性(天線輻射效率)的 測定方法。 首先，將被測定物5安裝在雙軸定位器4。此時，將被 測定物5設置成水平狀態。又，在測定開始之前，網路分 析器8將連接於被測定物5之高頻線路8A、與連接於測定 用天線6之高頻線路犯直接連結，以針對高頻線路8a、 8B所造成之損耗份量進行刻度之修正（校正）。 接著，操作雙軸定位器4之旋轉部4A、4B，將被測定 物5的角度定位在方位角0與仰角0皆為〇。的位置。在此 :態下，使用網路分析器8，藉測定用天線6來接收由被測 定物5(被測定天線5A)所放射之水平偏波，測定此時之參數 S21(R0”）。又’當結束了被測定物5在}個角度之參 數S21(R〇, 〇。，0)的測定後，則操作雙轴定位器4之方位 角方疋轉部4A，將被測定物5之方位角0增加1〇。以再次進 订參數S21(R〇, 1〇。，0〇)的測定。在方位角0為〇〇〜36〇〇之範 圍重複此項操作。 又，當被測定物5於方位角0方向旋轉丨圈後，使用 、同路刀析器8 ’藉測定用天線6來接收由被測定物5(被測定 天線5A)所放射的垂直偏波。此時係使用天線支撐具7，將 測定用天線6所測定之偏波從水平偏波切換成垂直偏波。 在該狀’4下，與上述之水平偏波時同樣，再度將被測定物5 16 200921117 4固疋在〇〇之狀態下，使雙軸定位器4之方位角旋 轉部4A旋鍾 斤 轉。猎此，在方位角Θ為0。〜360。之範圍以例如 母二㉝定方位W方向的參數S21(R，θ，〇。）。 ^結束了將仰角必固定於〇。時之測定後，操作雙抽定 态之仰角旋轉部4B，將被測定物5之仰角必增加1〇。。 在°亥狀態下’再次使方位角Θ於0。〜360。之範圍内每隔1〇。 ^ Vi 。 订對於水平偏波及垂直偏波之參數S2i(R，0， \〇 )的測定。在方位角0為〇。〜360。之範圍及仰角0為 0。〜18〇。之範圍重複以上操作，以測定在各方位角0與仰角 0 之參數 S2l(R， θ，0)。 、又，在結束了對所有方位角0及仰角分之測定後，對 於各方2位角Θ及仰角0予以加算水平偏波之測定結果的平 方S2i2(R’ Θ, 0)、以及垂直偏波之測定結果的平方s2i2(r， ，必）以算出最終之參數S2i的平方S212(r, 0，^)。 ，時’水平偏波之測定結果與垂直偏波之測定結果，並非 ，藉由網路分析器8所载之以對數表示㈣的測定值，而 是以轉換成真數之數值進行加算。 最後，根據水平偏波之測定結果及垂直偏波之測定結 果’對參數S尊，Θ，幻進行全空間之球面積分，根據 以下之數學式1來算出被測定物5的輻射效率”（被測定天 線5A的天線特性）。 (數學式1) 4_2SS2l2(R〇，M) sin θ Δ Μ θ η = —-Θ~±— __[Technical Field] The present invention relates to an electromagnetic wave measuring apparatus which is suitable for measuring electromagnetic waves radiated by, for example, a mobile phone or the like. [Prior Art] In the electromagnetic wave measuring device, it is known to arrange an object to be measured such as a mobile phone in a small radio wave non-sound box, and to measure the radiation efficiency of the antenna provided in the object to be measured (for example, Refer to Patent Document 丨, 2). Further, Patent Document 1 discloses that a radio wave absorption sheet used in a specific frequency band is provided inside a radio wave non-sound box in order to provide a small and inexpensive measurement space. At this time, the radio wave absorption sheet has a radio wave absorption characteristic in the measurement frequency band of the electromagnetic wave. Therefore, the composition of the mobile phone corresponds to the frequency bandwidth of the mobile phone: different different electromagnetic wave absorption sheets are used. That is, for example, a radio wave absorption sheet having a radio wave absorption characteristic of 纟700 to 900 MHz is used for the observation of the Z-belt system; a radio wave absorption sheet having a radio wave absorption characteristic is used for the UGHz band system; and 纟i 75 to 2 ggHz is used for the 19 GHz band system. A radio wave absorption sheet having radio wave absorption characteristics; a radio wave absorption sheet having radio wave absorption characteristics at 35 to 2.65 GHz for 25 gHz (four). Further, Patent Document 2 discloses a configuration in which an antenna for measuring a disk to be measured is placed in a anechoic chamber so as to be movable. At this time, by adjusting the position of the object to be measured and the antenna for measurement, even if the electromagnetic wave radiated from the object to be measured is reflected in the anechoic chamber, the intensity of the combined reflected wave can be reduced by the interference of a plurality of reflected waves. In the electromagnetic wave measuring device of Patent Document 1, the frequency T width that can be measured is subjected to radio waves. [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei. No. Hei. The absorption zone can be absorbed by the band. Therefore, for example, when measuring the characteristics of a mobile phone with a wide frequency band of a radio frequency band of a radio frequency band, it is necessary to have a plurality of wave-waveless boxes different in the wave absorption sheet, and the like. The radio waves are measured without a sound box. As a result, the measurement time is long, and a large space is required due to the placement of a plurality of radio wave soundless boxes. On the other hand, when an electric wave absorbing sheet which absorbs electromagnetic waves in a wide-band domain is used, since the radio wave absorbing sheet is large, the radio wave-free box tends to be enlarged. Furthermore, in the electromagnetic wave measuring apparatus of the patent document 2, since the measurement object and the stylus for the stylus and the line are determined at each measurement, it is necessary to obtain the object to be measured and the measurement antenna before the start of the measurement. Positional relationship. Therefore, it takes a lot of time to prepare before the measurement, and there is a problem that the work efficiency is low. The present invention has been proposed by the above-mentioned problems of the prior art, and 2 is to provide an electromagnetic wave measuring device capable of using a small-sized electric waveless box to perform characteristics for an object to be measured which emits a plurality of electromagnetic waves. In order to solve the above problems, Shen* Kuizhi # 4% τ 辱 辱 范围 范围 第 第 第 第 , 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁 电磁The electric wave-absorbing object to be measured is provided in the (four) radio wave non-sounding box as the measurement target; and the 200921117/belt antenna is placed in the radio wave-free box opposite to the object to be measured. An electromagnetic wave of the object to be measured; wherein the object to be measured' emits electromagnetic waves having a complex frequency band; the radio wave absorber has a high absorption in a specific frequency band of i or more bands of electromagnetic waves emitted from the object to be measured Characteristic, and other frequency bandwidths including the remaining one or more frequency bands of the electromagnetic waves emitted by the object to be measured have low absorption characteristics; the metal casings of the radio waves have no phase, and are opposite to each other When the electromagnetic wave radiated by the object to be measured is reflected by one of the two opposing surfaces and is incident on the first reflection path of the measurement antenna, the length of the first reflection path is L1, and the object is radiated by the object to be measured. The length of the second reflection path of the electromagnetic wave reflected by the other two opposite surfaces and incident on the measurement antenna is L2, and the other wavelength bands of the radio wave absorber having low absorption characteristics are included. When the wavelength of the center frequency between the maximum frequency and the minimum frequency is set to be the same, the difference ΔL between the lengths L1 and L2 of the first and second reflection paths is set to a range of 0_25 λ or more and 0.5 or less. In the invention of claim 2, the radio wave absorber has high absorption characteristics in a high frequency bandwidth equal to or higher than a minimum frequency band included in the specific frequency band, and the frequency bandwidth includes less than The frequency band of the specific frequency band has low absorption characteristics as the low frequency bandwidth of the other frequency band. In the invention of claim 3, the metal basket system is formed in a quadrangular cylindrical shape; the measuring antenna and the object to be measured The electromagnetic wave absorber is used in the invention in the fourth aspect of the invention. The carbon-containing radio wave absorbing material is formed into a pyramid shape or a tapered shape. In the invention of claim 5, the measurement antenna has a non-directionality in a frequency band of electromagnetic waves having low absorption characteristics in the radio wave absorber. According to the preparation of the first paragraph of the patent application scope; in the i or more frequency bands included in the other frequency bandwidths in which the absorption characteristics of turtles are low, the wavelength of the center frequency between the maximum frequency and the minimum frequency is set to be again The measurement antenna is disposed at a position where the difference between the lengths L1 and L2 of the first and second reflection paths is 〇25 or more and 〇5 or less. Therefore, even in the electromagnetic internal reflection in which the absorption characteristics of the radio wave absorber are low, the two reflected waves reflected on the two opposite surfaces are phase-difference due to the difference AL between the first and second reflection paths, and interfere with each other. And credit sales. Straight =, even if the electromagnetic wave having a low absorption characteristic of the radio wave absorber can suppress the influence of the reflected wave, it can increase the measurable frequency band. For example, when the mobile power of the electromagnetic wave in the complex frequency band can be measured, the electromagnetic wave of all frequency bands can be omitted in the single-waveless sound box, and the helmet I can be used for the purpose of the needle. Knowing the technology to use a complex number of waves to the heart, can improve the efficiency of the work (four). Further, the absorption characteristics of the radio wave absorber are widened to the lightning-absorbing body, and the absorption characteristics of the radio-acoustic wave-absorbing body of the radio wave-free box can be made smaller than the wavelength of the palm wave to determine the position of the measurement antenna. Therefore, according to the electromagnetic arrangement, it is not necessary to determine the position of the antenna for the measurement of the 200921117, and the position where the influence of the wave is small. Actually, the electromagnetic wave measurement is performed to find the reflection, and the preparation work before the measurement can be simplified, and the invention according to the second application of the patent application scope can be improved. The radio wave absorber has a high frequency bandwidth above the lowest frequency band included in the specific frequency band, and has high Absorption characteristics, low frequency band I as another frequency bandwidth in a frequency band containing a frequency band lower than a specific frequency bandwidth: 'has low absorption characteristics. Because & 'high-frequency electromagnetic waves above a certain frequency band, it can be absorbed by a radio wave absorber to suppress the occurrence of reflected waves. The n-side 'frequency is lower than the specific frequency, and cannot be absorbed by the radio wave absorber. Reflected inside the metal case. However, since the measurement antenna is arranged such that the difference AL is generated in the plurality of reflection paths, a plurality of reflected waves can be interfered and canceled, and the influence of the reflected waves can be suppressed. Further, compared with the case where the radio wave absorber is used to absorb low-frequency electromagnetic waves, the radio wave absorber can be made small, and the radio wave-free box can be miniaturized. According to the invention of claim 3, the measuring antenna and the object to be tested are disposed at positions spaced apart from each other in the axial direction of the metal casing and offset from the center on a diagonal line of the quadrangular cross section, and therefore, Compared with the case where the measurement antenna and the object to be measured are disposed at the center position on the diagonal line of the cross section, the difference AL can be generated in the plurality of reflection paths, and the influence of the reflection wave can be suppressed by the mutual interference of the plurality of reflection waves. . In addition, since the measuring antenna and the object to be measured are arranged on the diagonal line of the quadrangular cross section, for example, the cross section can be formed in a square shape, and the cross section can be symmetric across the diagonal line. . Therefore, the horizontal polarization and the vertical deviation of the measurement of the object to be measured by the measurement antenna are 200921117 :, and the polarization can be obtained with substantially the same characteristics. When the attenuation amount of the positive space is determined, the polarization characteristics of the square can be determined by correcting the polarization characteristics of the arbitrary square, and the efficiency of the operation can be improved. According to the invention of claim 4, the radio wave (4) (4) is formed into a pyramid shape or a taper shape by the radio wave absorbing material containing stone, so that when the protruding size of the radio wave absorber protruding from the metal casing is increased, Absorbs electromagnetic waves on the low frequency side. At this time, when the protruding size of the radio wave absorber becomes large, the overall shape of the radio wave non-ring box also becomes large. On the other hand, in the present invention, the electromagnetic waves on the low-frequency side can suppress the influence by interfering with a plurality of reflected waves. Therefore, the illuminable frequency bandwidth can be expanded while reducing the protruding size of the radio wave absorber. According to the invention of claim 5, the measuring antenna has no directivity in the frequency band in which the absorption characteristics of the radio wave absorber are low. Here, when the measuring antenna has directivity, it is not affected by the reflected waves from the surroundings, and only the direct wave that is directly incident on the measuring antenna from the object to be measured is received. However, the measurement antenna tends to increase in size due to the improvement of the directivity of the measurement antenna, and the measurement antenna cannot be placed in the small radio wave non-sound box. Therefore, in order to be disposed in a small radio wave non-sound box, the frequency band of the radio wave absorber having a low absorption characteristic (for example, the band on the low frequency side) is such that the antenna for measurement has no directivity, in addition to the direct wave. In the present invention, since a plurality of reflected waves interfere with each other, even if the reflected wave is received by the measuring antenna, the influence of the reflected wave can be suppressed, and the measurement is measured. The characteristics of the direct wave of matter. [Embodiment] 10 200921117 Hereinafter, an electromagnetic wave measuring apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In FIG. 1 to FIG. 4, the radio wave-free case i is a metal case 2 formed into a box shape by using an aluminum plate having a thickness of, for example, about 1 to 2 mm, and a radio wave absorber provided inside the metal case 2. 3 components. Also, the radio wave has no ring! In addition to blocking electromagnetic waves from the outside, it also prevents reflection of internal electromagnetic waves. The metal body 2 is formed to have a length of, for example, about 5 〇 to i 〇〇 cm in the width direction (χ direction), the axial direction 〇r direction, and the height direction (two directions). Further, the 'metal casing 2' has a front wall surface 2A and a rear wall surface 2B on both sides in the axial direction, in the real sound too a; Vh, the left wall surface 2c and the right wall surface on both sides of the hunger visibility direction, and The top surface 2E and the bottom surface 2 on both sides in the height direction are formed at this time, and the opposing wall faces 2A, 2B' form opposite faces facing each other. Further, the left and right wall faces 2C and 2D also face opposite faces, and the top face 2E and the bottom face 2F also face opposite faces. Further, the left and right wall faces 2C, 2D, the top face 2E, and the bottom face I are formed in a quadrangular cylindrical shape in the direction of the extension axis, and the cross section (xz + face) orthogonal to the glaze direction is formed into a square * ^ 0 A _ 耆 is closed at both end sides of the axial direction by the i-plane 2A and the rear wall surface 2B. In order to insert 诒 and 1 into the right wall surface 2D, the door 2G is attached in order to insert the breaking measurement & 5 described later into the metal basket. 0, U can be opened and closed in size m吏 using, for example, a carbon-containing radio wave absorbing material, forming a pyramid shape or a taper of the outer protrusion, toward the metal · 'radio wave absorber 3, when the object 5 is emitted 200921117 In the case of electromagnetic waves of several bands, the frequency band of the i or more frequency bands including the electromagnetic waves emitted from the object 5 is highly absorptive, and the other frequency of the remaining one or more of the electromagnetic waves emitted by the object 5 to be measured is included. Bandwidth 'has low absorption characteristics. Specifically, as shown in FIG. 6, the object 5 to be measured is, for example, an action of radiating a plurality of bands of electromagnetic waves of a band 80 〇 mHz, a band of 900 MHz, a band of 1.5 GHz, a band of 1.9 GHz, a band of 2.5 GHz, and a band of 5 GHz. In the case of telephone, the radio wave absorber 3 has a high frequency absorption characteristic in a band of 1.5 GHz band to 5 GHz band, and has low absorption characteristics in the other frequency band including the remaining 8 〇〇 MHz band and 90 〇 Mhz band. . Therefore, the high frequency bandwidth (1.5 GHz band to 5 GHz band) above the minimum frequency band (1.5 GHz band) included in the specific frequency bandwidth has, for example, a higher absorption characteristic than -20 dB, and a frequency band lower than a specific frequency band. The low frequency bandwidth '(8 〇〇 MHz band, 9 〇〇 MHz band) has a lower absorption characteristic than a 20 dB. The two-axis positioner 4, as shown in Fig. 2, is disposed on the side of the rear wall 2; 8 in the axial direction of the radio wave box portion. Further, the biaxial positioner 4 is provided with an azimuth rotation portion 4A' composed of an electric motor or the like, and the azimuth rotation portion 4A' is rotated about the azimuth angle 0 direction around the 01 axis parallel to the height direction. The upper portion of the biaxial positioner 4 is provided with an elevation rotation portion 4B that rotates in the elevation angle 0 direction around the 02 axis parallel to the axial direction (γ direction) using, for example, a plurality of gears or the like. The object to be measured 5 is attached to the elevation rotation unit 4B. The biaxial positioner 4 rotates the object 5 around the two axes of the first axis and the second axis that are orthogonal to each other to determine the object to be measured. The azimuth angle 0 and the elevation angle 0 of 5. The object to be measured 5 is attached to the elevation rotation portion 4B, and as shown in Fig. 5, 12 200921117 is rotated by the biaxial positioner 4 around the two axes of the first axis and the second axis. Further, the object to be measured 5 is constituted by, for example, a mobile phone, a mobile terminal, or the like, and has a measurement antenna 5'' as a measurement target for measuring radiation efficiency. The antenna to be measured 5 A' For example, a whip antenna, a built-in chip antenna, or the like is formed. The object to be measured 5 can be applied to a mobile phone capable of emitting electromagnetic waves of a plurality of bands such as an 800 MHz band, a 900 MHz band, a 1.5 GHz band, a '1.9 GHz band, a 2-5 GHz band, and a 5 GHz band. Although an electromagnetic wave capable of illuminating five frequency bands is exemplified, it is not necessarily an electromagnetic wave capable of emitting five frequency bands, and it is sufficient that electromagnetic waves of two or more frequency bands can be radiated. The measuring antenna 6 is as shown in FIGS. 2 to 4 . As shown in the figure, the inside of the radio wave non-sound phase 1 is disposed, for example, in the axial direction before the wall surface 2A side. Further, the measurement antenna 6 is attached to the antenna support 7 and is separated from the object 5 in the axial direction (γ direction). The opening distance R〇 is in an oppositely disposed state. The measuring antenna 6 is configured by, for example, a small biconical antenna (bican), and can selectively measure either one of a horizontal depolarization wave and a vertical depolarization wave. In this case, the measurement antenna 6 switches the measured polarization wave using the antenna support 7. Further, the measurement antenna 6 has a low-frequency bandwidth (for example, an 800 MHz band and a 900 MHz band) having a low absorption characteristic of the radio wave absorber 3. Non-directional. Also, measuring days 6 is connected to a network analyzer 8 to be described later. Here, the object to be measured 5 and the antenna for measurement 6 are respectively located on the diagonal line D_D of the cross section of the square, and the position is shifted from the center to the width direction by 5 1 . The position of the object to be measured 5 and the antenna for measurement 7 are placed on the upper side of the left slope of the cross section, for example, and are arranged in the width direction (X direction) of 13 200921117. The position close to the left wall surface 2C (compared to the right wall surface 2D) is placed in the height direction (Z direction) at a position close to the top surface 2E (relative to the bottom surface 2F). At this time, some of the electromagnetic waves directed from the object 5 to the measurement antenna 6 are reflected on the left and right wall surfaces 2C and 2D, respectively, and two reflected waves are generated. In addition, since the object to be measured 5 and the measurement antenna 6 are disposed at a position deviated from the center of the cross section, the electromagnetic wave radiated from the object 5 is reflected on the left wall surface 2C and is incident on the measurement antenna 6. When the length of the left reflection path is L11' and the electromagnetic wave radiated by the object 5 is reflected on the right wall surface 2D and the length of the right reflection path of the measurement antenna 6 is L12, the length of the two reflection paths is L11. L12 is not the same. Further, when the frequency of the low-frequency bandwidth of the radio wave absorber 3 is low (for example, the 800 MHz band and the 900 MHz band), the center frequency (for example, 892 MHz) between the minimum frequency (for example, 824 MHz) and the maximum frequency (for example, 960 MHz) When the wavelength is λ, the object to be measured 5 and the measurement antenna 6 are arranged such that the difference between the lengths L11 and L12 of the left and right reflection paths ΔLU^Ll'l L11 - L12|) is in the range of 0_25λ or more and 0.5λ or less (0.25). The position of person $8 1^1$0.5; 1). In the same manner, a part of the electromagnetic wave from the object 5 to be measured to the measurement antenna 6 is reflected on the top surface 2Ε and the bottom surface 2F of the upper and lower sides to generate two reflected waves. At this time, the electromagnetic wave radiated by the object 5 is reflected on the top surface 2Ε, and the length of the reflection path on the upper side of the measurement antenna 6 is [2 1, and the electromagnetic wave emitted from the object 5 is on the bottom surface 2F. When the length of the reflection path that is reflected and incident on the lower side of the measurement antenna 6 is L22, the lengths L21 and L22 of the two reflection paths 14 200921117 are not the same. Further, the object to be measured 5 and the measurement antenna 6 are disposed such that the difference between the lengths L21 and L22 of the upper and lower reflection paths is ΔB 2 (eight is 〇.25λ or more 〇5 and the following range (〇25u △ L2S 0.5 Λ ) The distance R1 between the measurement object 5 and the rear wall surface 2 is different from the distance R2 between the measurement antenna 6 and the front wall surface 2A. In this case, the electromagnetic wave from the object 5 to the measurement antenna 6 is A part of the front and rear wall surfaces 2A and 2B are respectively reflected and two reflected waves are generated. Further, since the distances R1 and R2 are different, electromagnetic waves radiated from the object 5 are reflected on the front wall surface 2A and incident on the measuring antenna 6 When the length of the front side reflection path is L3, and the electromagnetic wave radiated from the object 5 is reflected by the rear wall surface 2B and is incident on the measurement antenna 6, the length of the side reflection path is L32, and the length of the two reflection paths is L3 1 . In addition, the measurement object 5 and the measurement antenna 6 are disposed such that the difference between the lengths L31 and L32 of the front and rear reflection paths /\L3 (ZiL3 = | L31 - L3 2| ) is 〇·25λ The location of the above range of .5λ (0.25; lgAL3 S 0 · 5) As shown in FIG. 2, the electromagnetic field measuring device for measuring the electromagnetic field emitted by the object to be measured 5 (measured antenna 5A) is connected to the antenna to be measured 5a via the high-frequency line 8A, and is high. The frequency line 8B is connected to the measurement antenna 6. At this time, one end side of the high-frequency line 8A, 8B is connected to the external network analyzer 8', and the other end side is inserted into the radio wave via the connection plate 9 provided on the front wall surface 2A. The network analyzer 8 receives the electromagnetic wave (high-frequency signal) sent from the antenna to be measured 5A using the measurement antenna 6. The network analyzer 8 calculates the supply. The parameter S21 of the ratio of the received power to the 15 200921117 6 is measured. The electric wave measuring device of the present embodiment has the above-described configuration, and the electromagnetic wave measuring device of the present embodiment has the above-described configuration. A method of measuring the antenna characteristics (antenna radiation efficiency) of the electromagnetic wave measuring device will be described. First, the object to be measured 5 is attached to the biaxial positioner 4. At this time, the object to be measured 5 is placed in a horizontal state. Before the start of the measurement, the network analyzer 8 directly connects the high-frequency line 8A connected to the object 5 to be connected to the high-frequency line connected to the measuring antenna 6, and the amount of loss caused by the high-frequency lines 8a and 8B is caused. Correction (correction) of the scale is performed. Next, the rotating portions 4A and 4B of the biaxial positioner 4 are operated to position the angle of the object 5 at a position where both the azimuth angle 0 and the elevation angle 0 are 〇. The network analyzer 8 receives the horizontal polarization wave radiated by the object 5 (measured antenna 5A) by the measurement antenna 6, and measures the parameter S21 (R0) at this time. Further, when the measurement of the parameter S21 (R〇, 〇, 0) of the object 5 at the end angle is completed, the azimuth angle rotation portion 4A of the biaxial positioner 4 is operated to measure the object 5 The azimuth 0 is increased by 1〇. The measurement of the parameter S21 (R〇, 1〇, 0〇) is again performed. Repeat this operation for azimuth angle 0 〇〇~36〇〇. When the object 5 is rotated in the direction of the azimuth angle 0, the vertical deflection wave emitted from the object to be measured 5 (the antenna 5 to be measured 5) is received by the measurement antenna 6 using the same blade analyzer 8'. . In this case, the antenna support 7 is used, and the polarization measured by the measuring antenna 6 is switched from the horizontal depolarization to the vertical depolarization. In the same state as in the case of the above-described horizontal depolarization, the object to be measured 5 16 200921117 4 is again fixed in the state of the crucible, and the azimuth rotation portion 4A of the biaxial positioner 4 is rotated. . Hunt this, the azimuth is 0. ~360. The range is, for example, the parameter S21 (R, θ, 〇.) in the W direction of the parent 2 33. ^ End of the elevation angle must be fixed to 〇. After the measurement, the elevation rotation unit 4B of the double-draw state is operated to increase the elevation angle of the object 5 by one. . In the °H state, the azimuth angle is again set to zero. ~360. Every 1 〇 in the range. ^ Vi. The determination of the parameter S2i(R, 0, \〇) for the horizontal and vertical deflections is set. The azimuth angle is 〇. ~360. The range and elevation angle 0 are 0. ~18〇. The above operation is repeated to determine the parameter S2l(R, θ, 0) at each of the angle 0 and the elevation angle 0. Furthermore, after the measurement of all azimuth angles 0 and elevation angles is completed, the squared S2i2 (R' Θ, 0) of the measurement result of the horizontal wave is added to each of the two corners and the elevation angle 0, and the vertical deviation is performed. The square of the measurement result of the wave s2i2 (r, , must) is to calculate the square S212 (r, 0, ^) of the final parameter S2i. The measurement result of the horizontal polarization and the measurement result of the vertical polarization are not, and the measured value represented by the logarithm (4) carried by the network analyzer 8 is added by the value converted into the true number. Finally, based on the measurement result of the horizontal depolarization wave and the measurement result of the vertical depolarization wave, the spherical area of the entire space is calculated for the parameter S, Θ, and illusion, and the radiation efficiency of the object 5 is calculated according to the following mathematical formula 1 ( The antenna characteristic of the antenna 5A is measured. (Math. 1) 4_2SS2l2(R〇,M) sin θ Δ Μ θ η = —ΘΘ±±— __
λ Ο2 G 17 200921117 又’在數學式⑴，Λ0表示測定頻率的波長，G表示測 定用天線6的增益。又，表示仰角0方向之測 增值’本實施形態中〇係為1〇。（△卜細仙㈣）^ ^ ’ ΔΜ示方位角Θ方向之敎角度差，在本實施形離 中△ 0 例如為 1〇。（八 0=%[radian])。 . —本實施形態’係使用上述之測定方法者，接著，將本 實施形態之使用電磁波測定裝置以測定韓射效率之情形與 在自由工間疋輻射效率之情形（理論值）相比較，以掌握其 偏差。將其結果在圖7中以實線表示。 又，將被測定物5及測定用天線6配置在橫截面之中 心〇並測定輜射效率以作為比較例之用，而與在自由空間 測定輻射效率之理論值相比較。將其結果在圖7中以虛線 表示。 再者，在本實施形態及比較例之情形，均是跨 8〇〇MHZ〜2.4GHZ的範圍進㈣射效率的敎。又，電波吸 收體3係使用含碳之5时的金字塔型物體，在腦z有— dB在3GHz有-30dB，在iogHz有-45dB的吸收特性。 再：’其等之吸收特性，係吸收體製造業者在目錄所示之 於遠場測定垂直入射特性時所示數值。 又’所使用的電波無響箱U金屬筐體2)，其寬度方向 (X方向）尺寸為58cm ’高度方向（z方向）尺寸為58cm，軸 方向（Y方向）尺寸為78em。又，被測定物5及測定用天線6 在電波吸收體3之吸收特性較低之電磁波的中心頻率，例 為900MHz左右時’係分別被配置在於寬度方向及高度方 18 200921117 向分別從橫截面之中心〇偏離4cm(5 1=<5 2=4咖）的位置。 又將被測定物5配置於與後壁面2B之距離R1為28cm的 位置，將/則定用天線6配置於與前壁面2A之距離R2為 的位置。再者，被測定物5與測定用天線6間的距離R〇被 設定成30cm。 另方面’在比較例的情形時’雖然使用與實施形態 相同的電波無響箱i，但被測定物5及測定用天線6係配置 在k截面的中心〇。又，將被測定物$配置於與後壁面 之距離R1為24cm的位置，且，將測定用天線6配置於與 前壁面2A之距離R2為24cm的位置。 根據圖7的結果，在比較例中，於8〇〇MHz〜2 4GHz的 範圍，相距於理論值的偏差為—15犯〜21犯。相對於此， 在本實施形態中’相距於理論值之偏差為_〇.刚〜i應， 較接近理論值。 若將行動電話之頻帶寬縮限，在824〜96〇MHz的帶域， 比較例之偏差為-0讀〜UdB，相對於此，本實施形態之 偏差為O.ldB〜0細。又，在17l〇〜2l7〇MHz的帶域，在比 較例之偏差為一 〇.ldB〜UdB，相對於此，在本實施形態的 偏差為0.2dB〜i.OdB。如所示，本實施形態中，可將相距於 理論值之偏差降低至± 1 ·〇dB以内。 又，將習知方法之使用球形定位器（响咖p〇siu繼r) 以測定遠場之輻射效率之情形，與本實施形態之情形進行 比較’以掌握其偏差。再者’在習知方法之情形，測定距 離（被測定物5與測定用天線6之間的距離）係以口咖作為 19 200921117 遠場之值，以對於被測定物進行全球面狀的測定。由其結 果可以了解，本實施形態與習知方法之偏差在±1 .OdB以 内，與遠場之測定結果一致。 如此，在本實施形態中’對於電波吸收體3之吸收特 性較低之頻帶寬所包含之1個以上頻帶中，將其最大頻率 與最小頻率間之中心頻率的波長設為Λ，此時，將測定用 天線6配置於，反射路徑之長度Lll、L21、L31與反射路 仅之長度 L12、L22、L32 之差 /\L1、AL2、Z\L3 為 〇25 λ以上0.5又以下範圍的位置。因此，即使是電波吸收體3 之吸收特性較低之電磁波在電波無響箱1内反射，在左壁 面2C、頂面2Ε、前壁面2Α與右壁面2D、底面2F、及後 壁面2Β所反射的2個反射波，藉反射路徑之差值ali、△ L2、△ L3而產生相位差，經彼此干涉而抵銷。其結果，即 使對電波吸收體3之吸收特性較低之電磁波，亦可抑制反 射波的影響，因而能擴大可供測定之頻帶寬。 — 在。平量可放射複數頻帶電磁波之被測定物5的 特性^如對具有_ΜΗζ帶〜5咖帶之多頻行動電話作 特14 :平里日夺，亦能在單一之電波無響箱内測定所有頻帶之 : ’’、、肩如習知技術般地使用複數個電波無響箱來測 定，而可提高測定作業的效率。 由於可預先掌握電波吸收體3之吸收特性較低的 電磁波，因此， B根據該電磁波之波長Λ來決定測定用天 線6的位置。田 U此’無蟫為了決定測定用天線6之位置， 而如省知技術般地邊杏 吧遠a際進仃電磁波測定邊尋找反射波影 20 200921117 響較少的位置，可簡化測金i n & '定則的準備作業而提高測定效率。 再者，電波吸收體3 ^ 在特定頻帶寬所包含之最低頻帶 (例如1.5GHz帶）以上的高頻 ▼寬’具有南吸收特性，而在 包含低於特定頻帶官# # _ 貝帶寬之頻帶的低頻帶寬（80_ζ帶、 900MHz帶），則具有低叨μ # -及收特性。因此，例如在使用多頻 行動電話以作為被測定及 π饭州疋物5時，在高頻側帶域 (1710〜2 170MHz)的雷磁妹，-Γ & m ^ 电磁波，可使用電波吸收體3來吸收， 以抑制反射波的發生ϋ面，在多頻行動電話之低頻 側之▼域（824 960MHz)的電磁波，無法由電波吸收體3來 吸收’會在金屬筐體2内反射。‘然*，由於係以在複數條 反射路徑產生差值紅卜^2、紅3之方式來配置測定用 天線6,因此能使複數個反射波彼此干涉而抵銷，可抑制反 射波的影響。 特別疋’電波吸收體3係使用含碳之電波吸收材料而 形成為金字塔形狀或錐狀，因此，藉著增大由金屬筐體2 突出之電波吸收體3的突出尺寸，則可吸收低頻側的電磁 波。此時，電波吸收體3之突出尺寸變大後，電波無響箱1 之整體形狀亦會變大。相對於此，在本實施形態中之低頻 側的電磁波，可藉由複數個反射波之相互干涉而抑制其影 響’因此，既能縮小電波吸收體3的突出尺寸又能擴大可 供測定之頻率的帶域。其結果，相較於將電波吸收體3之 吸收特性擴大頻域，使用電波吸收體3來吸收低頻電磁波 之情形時，可縮小電波吸收體3，達到電波無響箱1的小型 化0 21 200921117 又’：定用天線6及被測定物5’係配置成在金屬复體 »上彼此隔開’ ^位在四角形橫截面之對角線d七 心0偏離的位置，因此，相較於將測定用天線6及 ㈠疋物5配置在橫截面之對角線d_d上的中心位置。之 情形時’可在複數條反射路徑產生差值仏、化，能利 用後數個反射波的相互干涉以抑制反射波的影響。 再者，由於係將測定用天線6及被測定物5配置在四 角形横截面之對角 '線Μ上’因此，可藉由例如將橫截面 形成為正方形的方式，使橫截面隔著對角線d_d而具有對 稱性。因此，在以測定用天線6接收被測定物5所放射之 水平偏波及垂直偏波時，在2種偏波可得到大致相同的特 =°其結果，例如在校正空間之衰減量時’可藉由測定任 一方之偏波特性，對於兩種偏波進行校正，而可提升測定 的作業效率。 又，測定用天線6在電波吸收體3之吸收特性較低之 低頻帶寬’係具無指向性。在此，當測定用天、線6具有指 向I1生時，不會受到來自周圍之反射波的影響僅會接收由 被測疋物5直接射入測定用天線6的直接波。然而其問題 在於，由於測定用天線6之指向性的提高會使測定用天線6 趨於大型化，而無法將測定用天線6配置在小型之電波無 響箱1内。因此，為了要能配置在小型之電波無響箱i内， 在電波吸收體3之吸收特性較低的低頻帶寬，測定用天線6 具無指向性，除直接波外亦接收反射波。此時，在本實施 形態中，係使複數個反射波相互干涉，因此，就算是在藉 22 200921117 測定用天線6而接收反射波的帶域，既能抑制反射波的影 響亦此測疋來自被測定物5之直接波的特性。 再者’在前述實施形態，被測定物5及測定用天線6 皆係配置在從橫截面之中心〇偏離的位置，然而，例如亦 了僅將被測疋物5及測定用天線6中任一方配置在從橫截 面的中心Ο偏離之位置。 又，在該實施形態中的電波吸收體3,係形成為金字塔 形狀或錐形，然而，例如形成為與習知技術相同之片狀者 亦可。 又’在該實施形態中的電波吸收體3所舉之例，在包 含4個頻帶（1.5GHz帶、ughz、2 5GHz、5GHz帶）之高頻 帶寬’具有高吸收特性’在包含2個頻帶（8〇〇MHz帶、 900MHz帶）之低頻帶寬，具有低吸收特性。然而，本發明 並不侷限於此，電波吸收體之構成亦可舉例為，在包含 900MHz帶〜5GHz帶之5個頻帶的高頻帶寬具有高吸收特 性’在包含1個頻帶（800MHz帶）之低頻帶寬具有低吸收特 性。在此情形’係將800MHz帶之最大頻率與最小頻率間之 中心頻率的波長設為λ ’以決定測定用天線等的位置。 再者，在前述實施形態的構成，係使用行動電話作為 被測定物5，但亦可使用能放射電磁波之其他機器。又， 在 前述實施形態，雖使用雙錐天線作為測定用天線6，但亦可 使用其他形式的天線。 【圖式簡單說明】 圖1係本發明之實施形態之電磁波測定裝置的前視Α 23 200921117 體圖。 圖2係從圖1中之箭頭n - π方向所見之電磁波測定裝 置的截面圖。 圖3係從圖2中之箭頭m-n[方向所見之電磁波測定裝 置的截面圖。 圖4係從圖2中之箭頭rv-rv方向所見之電磁波測定裝 置的截面圖。 圖5係將圖2中之被測定物周圍予以放大的立體圖。 圖6係實施形態之被測定物的頻帶與電波吸收體之吸 收特性的關係說明圖。 圖7係表示實施形態及比較例之天線輻射效率與理論 值之偏差的特性線圖。 【主要元件符號說明】 1 電波無響箱 2 金屬筐體 2A 前壁面（對向面） 2B 後壁面（對向面） 2C 左壁面（對向面） 2D 右壁面（對向面） 2E 頂面（對向面） 2F 底面（對向面） 3 電波吸收體 4 雙軸定位器 5 被測定物 24 200921117 6 測定用天線 8 網路分析器 25λ Ο2 G 17 200921117 Further, in the mathematical expression (1), Λ0 represents the wavelength of the measurement frequency, and G represents the gain of the measurement antenna 6. Further, the value of the elevation angle 0 is increased. In the present embodiment, the enthalpy is 1 〇. (△卜细仙(四)) ^ ^ ' ΔΜ indicates the angle difference between the azimuth and the Θ direction. In the present embodiment, Δ 0 is, for example, 1 〇. (eight 0 =% [radian]). In the present embodiment, the above-described measurement method is used, and then the electromagnetic wave measuring device according to the present embodiment is compared with the case where the radiation efficiency is measured at a free work (theoretical value), Master the deviation. The result is shown by a solid line in FIG. Further, the object to be measured 5 and the measurement antenna 6 were placed in the center of the cross section, and the emission efficiency was measured as a comparative example, and compared with the theoretical value of the measurement of the radiation efficiency in the free space. The result is shown by a broken line in Fig. 7. Further, in the case of the present embodiment and the comparative example, the efficiency of the (four) injection efficiency was in the range of 8 〇〇 MHZ to 2.4 GHz. Further, the radio wave absorber 3 is a pyramid-shaped object when carbon 5 is used, and has a -dB of -30 dB at 3 GHz in the brain z and -45 dB in iogHz. Further: 'The absorption characteristics of the absorbers are the values shown by the absorber manufacturer in the far field to determine the normal incidence characteristics as shown in the catalog. Further, the radio wave non-sound box U metal casing 2 used had a width (X direction) dimension of 58 cm 'the height direction (z direction) dimension of 58 cm, and the axial direction (Y direction) dimension of 78 cm. In addition, when the center frequency of the electromagnetic wave having a low absorption characteristic of the electromagnetic wave absorber 3 is about 900 MHz, the measurement object 5 and the measurement antenna 6 are arranged in the width direction and the height side 18, respectively. The center 〇 deviates from the position of 4 cm (5 1 = < 5 2 = 4 coffee). Further, the object to be measured 5 is placed at a position where the distance R1 from the rear wall surface 2B is 28 cm, and the fixed antenna 6 is placed at a position R1 from the front wall surface 2A. Further, the distance R 间 between the object 5 and the measurement antenna 6 was set to 30 cm. On the other hand, in the case of the comparative example, the radio wave box i is the same as that of the embodiment, but the object 5 and the measuring antenna 6 are arranged at the center k of the k-section. Further, the object to be measured $ is placed at a position at a distance R1 of 24 cm from the rear wall surface, and the measurement antenna 6 is placed at a position at a distance R2 from the front wall surface 2A of 24 cm. According to the results of Fig. 7, in the comparative example, in the range of 8 〇〇 MHz to 2 4 GHz, the deviation from the theoretical value is -15 to 21 commits. On the other hand, in the present embodiment, the deviation from the theoretical value is _〇. just ~ i should be closer to the theoretical value. When the frequency bandwidth of the mobile phone is narrowed, the deviation of the comparative example is -0 read to UdB in the band of 824 to 96 〇 MHz. On the other hand, the deviation of this embodiment is O.ldB to 0. Further, in the band of 17l 〇 to 2l7 〇 MHz, the deviation in the comparative example is 〇.ldB to UdB, whereas the deviation in the present embodiment is 0.2 dB to i.OdB. As shown, in the present embodiment, the deviation from the theoretical value can be reduced to within ± 1 · 〇 dB. Further, the conventional method is used to measure the radiation efficiency of the far field by using a spherical locator (sounding coffee p〇siu followed by r) to compare the situation of the present embodiment to grasp the deviation. In the case of the conventional method, the measurement distance (the distance between the object to be measured 5 and the measurement antenna 6) is a value of the far field of 19 200921117 by the mouth coffee, and the global measurement of the object to be measured is performed. . As can be seen from the results, the deviation between the present embodiment and the conventional method is within ±1.OdB, which is consistent with the measurement result of the far field. As described above, in the present embodiment, the wavelength of the center frequency between the maximum frequency and the minimum frequency is set to Λ in one or more frequency bands included in the frequency bandwidth in which the absorption characteristics of the radio wave absorber 3 are low. The measurement antenna 6 is disposed such that the difference between the lengths L11, L21, and L31 of the reflection path and the lengths L12, L22, and L32 of the reflection path/\L1, AL2, and Z\L3 is 〇25 λ or more and 0.5 or less. . Therefore, even if the electromagnetic wave having low absorption characteristics of the radio wave absorber 3 is reflected in the radio wave non-sound box 1, it is reflected on the left wall surface 2C, the top surface 2Ε, the front wall surface 2Α, the right wall surface 2D, the bottom surface 2F, and the rear wall surface 2Β. The two reflected waves are phase-shifted by the difference ali, ΔL2, and ΔL3 of the reflection paths, and are offset by mutual interference. As a result, even if the electromagnetic wave having low absorption characteristics of the radio wave absorber 3 can suppress the influence of the reflection wave, the frequency bandwidth available for measurement can be expanded. — at. The characteristics of the measured object 5 which can radiate the electromagnetic wave of the complex frequency band. For example, for a multi-frequency mobile phone with _ΜΗζ带~5 咖带, it can be measured in a single radio wave box. For all frequency bands: '', the shoulder is measured using a plurality of radio wave non-sounding boxes as is conventionally known, and the efficiency of the measurement operation can be improved. Since the electromagnetic wave having low absorption characteristics of the radio wave absorber 3 can be grasped in advance, B determines the position of the measurement antenna 6 based on the wavelength Λ of the electromagnetic wave. Tian U this 'innocence in order to determine the position of the antenna 6 for measurement, and as the technology knows the technology, the side of the apricot is far away from the electromagnetic wave measurement while looking for the reflection wave shadow 20 200921117 ringing less position, can simplify the gold measurement in & 'Standard preparation work to improve measurement efficiency. Furthermore, the radio wave absorber 3 ^ has a south absorption characteristic at a high frequency band width of a minimum frequency band (for example, a 1.5 GHz band) included in a specific frequency band, and a frequency band containing a bandwidth lower than a specific band of the specific band. The low frequency bandwidth (80_ζ, 900MHz band) has a low 叨μ # - and receive characteristics. Therefore, for example, when a multi-frequency mobile phone is used as the measured and π-Imperial object 5, in the high-frequency side band (1710 to 2 170 MHz), the magnetic resonance wave, -Γ & m ^ electromagnetic wave, can be used for electromagnetic wave absorption. The body 3 absorbs and suppresses the occurrence of the reflected wave, and the electromagnetic wave in the ▼ field (824 960 MHz) on the low-frequency side of the multi-frequency mobile phone cannot be absorbed by the radio wave absorber 3 and is reflected in the metal casing 2. In the case of the measurement antenna 6, the measurement antenna 6 is arranged such that the plurality of reflection waves are generated in a plurality of reflection paths, so that the plurality of reflection waves can interfere with each other and cancel the influence of the reflected waves. . In particular, the radio wave absorber 3 is formed into a pyramid shape or a taper shape by using a carbon wave-containing radio wave absorbing material. Therefore, by increasing the protruding size of the radio wave absorber 3 protruding from the metal casing 2, the low-frequency side can be absorbed. Electromagnetic waves. At this time, the protruding shape of the radio wave absorber 3 becomes large, and the overall shape of the radio wave non-sound box 1 also becomes large. On the other hand, in the electromagnetic wave on the low-frequency side in the present embodiment, the influence of the plurality of reflected waves can be suppressed by mutual interference. Therefore, the protruding size of the electromagnetic wave absorber 3 can be reduced and the frequency available for measurement can be expanded. Band. As a result, when the radio wave absorber 3 is used to absorb the low-frequency electromagnetic wave, the radio wave absorber 3 can be reduced in comparison with the case where the absorption characteristic of the radio wave absorber 3 is widened in the frequency domain, and the radio wave absorber 3 can be reduced to achieve miniaturization of the radio wave box 1 0 2009 2009117 Further, 'the fixed antenna 6 and the object to be measured 5' are arranged to be spaced apart from each other on the metal complex», and the position of the diagonal line d of the square cross-section is offset from the center of the square. Therefore, compared with The measuring antenna 6 and the (1) object 5 are disposed at a center position on the diagonal d_d of the cross section. In the case of the case, the difference can be generated in a plurality of reflection paths, and the mutual interference of the plurality of reflected waves can be utilized to suppress the influence of the reflected waves. Furthermore, since the measuring antenna 6 and the object to be measured 5 are arranged on the diagonal 'line 四' of the quadrangular cross section, the cross section can be diagonally separated by, for example, forming the cross section into a square shape. The line d_d has symmetry. Therefore, when the horizontal deflection wave and the vertical deflection wave emitted by the object 5 are received by the measurement antenna 6, the result is substantially the same as the result of the two types of polarization, for example, when the attenuation amount of the correction space is ' By measuring the polarization characteristics of either side, the two types of polarization are corrected, and the efficiency of the measurement can be improved. Further, the low-frequency bandwidth of the measuring antenna 6 having a low absorption characteristic in the radio wave absorber 3 has no directivity. Here, when the measurement day and line 6 are directed to I1, the direct wave that is directly incident on the measurement antenna 6 by the object to be detected 5 is received without being affected by the reflected waves from the surroundings. However, the measurement antenna 6 tends to increase in size because the directivity of the measuring antenna 6 is increased, and the measuring antenna 6 cannot be placed in the small radio wave non-sounding box 1. Therefore, in order to be able to be disposed in the small radio wave non-sound box i, the measuring antenna 6 has no directivity in the low-frequency bandwidth in which the absorption characteristics of the radio wave absorber 3 are low, and the reflected wave is received in addition to the direct wave. In this case, in the present embodiment, since a plurality of reflected waves interfere with each other, even if the band of the reflected wave is received by the measuring antenna 6 of 22 200921117, the influence of the reflected wave can be suppressed. The characteristics of the direct wave of the object 5 to be measured. In the above-described embodiment, the object to be measured 5 and the antenna for measurement 6 are disposed at positions offset from the center of the cross section. However, for example, only one of the object 5 to be measured and the antenna for measurement 6 are also included. It is placed at a position offset from the center of the cross section. Further, the radio wave absorber 3 of the embodiment is formed in a pyramid shape or a taper shape. However, for example, it may be formed into a sheet shape similar to the prior art. In the example of the radio wave absorber 3 according to the embodiment, the high-frequency bandwidth 'having high absorption characteristics' in the four frequency bands (1.5 GHz band, ughz, 25 GHz, and 5 GHz band) includes two bands. The low frequency bandwidth (8 〇〇 MHz band, 900 MHz band) has low absorption characteristics. However, the present invention is not limited thereto, and the configuration of the radio wave absorber may be exemplified by having a high absorption characteristic in a high frequency band including five frequency bands of a band of 900 MHz to 5 GHz, and including one frequency band (800 MHz band). The low frequency bandwidth has low absorption characteristics. In this case, the wavelength of the center frequency between the maximum frequency and the minimum frequency of the 800 MHz band is λ ' to determine the position of the measuring antenna or the like. Further, in the configuration of the above-described embodiment, a mobile phone is used as the object 5 to be measured, but another device capable of radiating electromagnetic waves may be used. Further, in the above embodiment, a biconical antenna is used as the measurement antenna 6, but other types of antennas may be used. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front view of an electromagnetic wave measuring apparatus according to an embodiment of the present invention. Fig. 2 is a cross-sectional view of the electromagnetic wave measuring device seen from the direction of the arrow n - π in Fig. 1. Fig. 3 is a cross-sectional view of the electromagnetic wave measuring device seen from the direction of the arrow m-n in Fig. 2; Fig. 4 is a cross-sectional view of the electromagnetic wave measuring device seen from the direction of the arrow rv-rv in Fig. 2. Fig. 5 is a perspective view showing an enlarged view of the periphery of the object to be measured in Fig. 2. Fig. 6 is an explanatory diagram showing the relationship between the frequency band of the object to be measured and the absorption characteristics of the radio wave absorber in the embodiment. Fig. 7 is a characteristic line diagram showing the deviation between the radiation efficiency of the antenna and the theoretical value in the embodiment and the comparative example. [Description of main component symbols] 1 Radio wave box 2 Metal case 2A Front wall (opposite side) 2B Rear wall (opposite side) 2C Left wall (opposite side) 2D Right wall (opposite side) 2E Top surface (opposite surface) 2F bottom surface (opposing surface) 3 Radio wave absorber 4 Biaxial positioner 5 Object to be measured 24 200921117 6 Measuring antenna 8 Network analyzer 25