200952257 九、發明說明： 【發明所屬之技術領域】 本發明係提供一種寬頻共平面波導饋入之對稱螺旋 單極生醫植入式天線，特別是指一種可提高頻寬且具有結 構精簡、面積輕薄短小可更微型化等優點，不僅可符合美 國聯邦通訊委員會(FCC)規定的植入式頻段，亦即是醫療 植入式通訊服務之402〜405MHz頻段所適合人體通訊之 頻帶且更方便植入人體。本發明之生醫植入式天線係採用 ® 微波陶瓷材料做為天線基板，並採用共平面波導饋入方式 設計出具有相對稱螺旋段之天線圖樣，可達到提高頻寬及 天線更微型化等使用效益。 【先前技術】 近年來微機電的研究，迅速促進了植入式生理訊號遙 測裝置的發展，也使得生物醫療元件微型化，將生理訊號 遙測裝置植入人體内，並進行檢驗量測生理資訊是未來的 醫療趨勢；但是如果天線的體積過大，植入人體比較困 難，所以發展微型植入天線是必要的。大部分人體植入式 微波生醫裝置系統應用於熱治療、監測生理參數、調節身 體功能，或對組織進行控制。研究也指出微波天線可以對 腫瘤細胞加溫又可稱為無線射頻熱療法，利用交流電造成 組織細胞離子的擾動摩擦而產生熱，進而使腫瘤細胞蛋白 質產生變性缺水凝固的現象，因此像蛋被加熱一樣，癌腫 瘤細胞便被固定而壞死，是安全有效的局部微創治療技 5 200952257 術’這種微創射頻熱治療技術，產生熱源的多寡與電流強 度和持續時間成正比，並與組織血流量和流速有密切的關 係。一般微波加溫治療所採用的頻率有433MHz、 915MHz、2.45GHz和5.8GHz等幾種。微波天線除了應用 於醫療和診斷外，也應用在植入式生醫裝置的通訊上，如 心臟起搏器、電擊器、GPS等。也有研究成功的將植入式 天線應用在人體視網膜上，採用低功耗的方式，在眼睛前 方的眼鏡鏡片内設置CMOS影像感測器（CMOS Image ® Sensor)，將可擷取視覺訊息並且轉換成眼睛能接受的信 號，代替眼内感光細胞的功能，再由射頻信號傳入眼内， 可幫助因為色素性視網膜炎（Retinitis Pigmentosa)，或老 年性黃斑病變（Age-Related Macula Degeneration)而失去 視覺的病患，恢復部分的視覺。利用植入式天線裝置來建 立身體和醫療設備之間的通訊連結，可直接從外部獲得人 體内的相關資訊。 天線位於無線通訊系統的前端，特性良好的天線系 ® 統，可以提高無線通訊系統的工作效率。很多植入式天線 的相關研究都採用堆疊或彎折微帶線方法和平面倒 F(PIFA)饋入的方式製作天線，優點為可以容易達到好的 頻寬；不過在製程上必需要鑽孔不僅提高製程困難度且容 易影響天線的特性。或者採用正方形、圓形、菱形螺旋等 等的電感性天線(Inductive Antennas)的設計方法能順利達 到生醫遙測的功能。在設計天線的過程中’選用的基板材 質、基板厚度、饋入點的位置、天線長度、天線型狀結構 200952257 都會影響天線特性的好壞。習知槽孔天線使用CPW饋入 之方式，比較常見的分別有電容式饋入和電感式饋入。電 容式饋入結構一般應用於迴圈天線、偶極天線等，電容式 饋入之設計因可具有較大的頻寬和容易取得匹配的特 性’所以常被應用於各式的天線饋入。 再方面，402〜405MHz是非常適合人體通訊之頻帶。 當全球還未規範植入式通訊裝置的專用頻段時，植入式裝 置系統和監控系統之間的通訊，大多採用磁耦合原理（等 ❹ 於是天線)的短程系統，缺點為數據傳輸率有限，且兩系 統之間的耦合距離較短。將402〜405MHz劃為醫療植入性 通訊服務(MICS)共用頻帶後，上述情況才改觀。 電磁輻射環境中，生物體所吸收的電磁波能量對該生 物體單位質量之比值定義為特定吸收率（SAR，Specific Absorption Rate)，單位為W/kg。長久暴露在電磁波環境 可能會造成某種程度的傷害，雖然還不能確電磁波對人體 的影響，但是根據美國IEEE/ANSIC95.1 1999的規定，1 ® 克組織受到30分鐘的電磁波輻射所產生之最大SAR值不 能超過1.6W/kg。而此規範目前已被美國聯邦通訊委員會 (Federal Communications Commission，FCC)戶斤採納。國際 非游離輻射保護委員會（International Commission on Non-Ionizing Radiation Protection，ICNIRP)則採用較寬鬆 的規定，即10克組織經6分鐘的電磁波輻射所產生之最 大SAR值不能超過2W/kg。 本發明採用美國IEEE/ANSI的安全規定，以電磁波 7 200952257 模擬軟體建立人體軟組織模型，模擬人體植入式天線輻射 電磁能量，並且評估是否符合人體軟組織之特定吸收率 (SAR)的安全範圍。 天線主要可分為四大部分：介質基板（Dielectric Substrate )、輻射金屬片（Radiating Patch )、接地平面 Ο200952257 IX. Description of the invention: [Technical field of the invention] The present invention provides a symmetric spiral monopole biomedical implantable antenna fed by a wide-band coplanar waveguide, in particular, a method for improving bandwidth and having a compact structure and area Lightweight and short, it can be more miniaturized, and it can not only meet the embedded frequency band specified by the Federal Communications Commission (FCC), but also the frequency band suitable for human communication in the 402~405MHz frequency band of medical implantable communication service. Into the human body. The biomedical implantable antenna of the invention adopts a microwave ceramic material as an antenna substrate, and adopts a coplanar waveguide feeding method to design an antenna pattern with a relatively spiral section, which can improve the bandwidth and the miniaturization of the antenna. Use benefits. [Prior Art] In recent years, research on microelectromechanics has rapidly promoted the development of implantable physiological signal telemetry devices, and also miniaturized biomedical components, implanted physiological signal telemetry devices into the human body, and conducted measurement and measurement of physiological information. Future medical trends; but if the size of the antenna is too large, it is difficult to implant into the human body, so the development of micro-implanted antennas is necessary. Most human implantable microwave biomedical device systems are used for thermal therapy, monitoring physiological parameters, regulating body function, or controlling tissue. The research also pointed out that the microwave antenna can warm the tumor cells and can be called radio frequency radiotherapy. It uses the alternating current to cause the disturbance of the tissue cell ions to generate heat, which causes the tumor cell protein to degenerate and dehydrate and solidify. Like heating, cancerous tumor cells are fixed and necrotic, which is a safe and effective local minimally invasive treatment technique. 200952257 This kind of minimally invasive radiofrequency thermal therapy technology produces a heat source proportional to the current intensity and duration, and is organized with tissue. Blood flow and flow rate are closely related. The frequencies used in general microwave heating therapy are 433MHz, 915MHz, 2.45GHz and 5.8GHz. In addition to medical and diagnostic applications, microwave antennas are also used in the communication of implantable biomedical devices, such as pacemakers, electric shocks, and GPS. There is also a successful application of implantable antennas on the human retina. Using a low-power method, a CMOS image sensor (CMOS Image ® Sensor) can be placed in the spectacle lens in front of the eye to capture visual information and convert it. A signal acceptable to the eye, in place of the function of the photoreceptor cells in the eye, and then transmitted to the eye by radio frequency signals, which may help to lose due to Retinitis Pigmentosa or Age-Related Macula Degeneration. The visual patient recovers part of the vision. The implanted antenna device is used to establish a communication link between the body and the medical device, and the relevant information in the human body can be directly obtained from the outside. The antenna is located at the front end of the wireless communication system, and the antenna system with good characteristics can improve the efficiency of the wireless communication system. Many researches on implantable antennas use the stacked or bent microstrip method and the planar inverted F (PIFA) feed to make the antenna. The advantage is that the bandwidth can be easily achieved; however, drilling must be required not only in the process. Improve the difficulty of the process and easily affect the characteristics of the antenna. Or the design method of Inductive Antennas such as square, circular, diamond spiral, etc. can successfully achieve the function of biomedical telemetry. In the process of designing the antenna, the selected substrate quality, substrate thickness, feed point position, antenna length, and antenna shape structure 200952257 will affect the antenna characteristics. Conventional slot antennas use the CPW feed method. The more common ones are capacitive feed and inductive feed. Capacitive feedthrough structures are generally applied to loop antennas, dipole antennas, etc. Capacitive feed designs are often used for various antenna feeds because of their large bandwidth and easy matching characteristics. On the other hand, 402~405MHz is a very suitable frequency band for human body communication. When the dedicated frequency band of the implantable communication device is not standardized in the world, the communication between the implanted device system and the monitoring system mostly uses a short-range system of the magnetic coupling principle (equal to the antenna), and the disadvantage is that the data transmission rate is limited. And the coupling distance between the two systems is short. This situation changed after the 402~405MHz was classified as the shared band of the Medical Implantable Communication Service (MICS). In the electromagnetic radiation environment, the ratio of the electromagnetic wave energy absorbed by the organism to the unit mass of the living body is defined as the Specific Absorption Rate (SAR) in units of W/kg. Long-term exposure to electromagnetic waves may cause some degree of damage. Although it is not possible to confirm the effects of electromagnetic waves on the human body, according to the US IEEE/ANSIC95.1 1999, 1 gram of tissue is subjected to the maximum of 30 minutes of electromagnetic radiation. The SAR value cannot exceed 1.6 W/kg. This specification has now been adopted by the Federal Communications Commission (FCC). The International Commission on Non-Ionizing Radiation Protection (ICNIRP) adopts a looser rule that the maximum SAR value of 10 grams of tissue after 6 minutes of electromagnetic radiation cannot exceed 2 W/kg. The invention adopts the IEEE/ANSI safety regulations of the United States, establishes a human soft tissue model with electromagnetic wave 7 200952257 simulation software, simulates the electromagnetic energy radiated by the human implanted antenna, and evaluates whether it meets the safety range of the specific absorption rate (SAR) of the human soft tissue. The antenna can be divided into four main parts: Dielectric Substrate, Radiation Patch, and Ground Plane.
(Ground Plane)與饋入網路（Feed Network)，每一部份 對天線的操作特性都具有影響性，一般為改變天線結構來 達到欲求特性的要求；天線在材料使用上，通常選擇導電 係數高的金屬’譬如：輻射金屬片與接地平面常用銅、銘 等材料。介質基板的部分，目前最常使用的基板是一般的 FR4、RO基板，雖然製作方便，但往往因為材料的^值’ 介電常數不高，而使天線的反射損失和頻寬不佳，縮 線的尺寸也比較困難。 、、、、天 本發明人即是有鑑於植入式天線必須更加微 易於植人人體且能提高外在監測系統與天線兩夕 輸效率，本發明—縮小天線面積、低料=傳 的架構’天線圖樣料為CPW饋人的設計具^頻 f式的優點為：易與微波電路元件相結合、饋^方^計 範特性不受基板厚度變 式和電 比例可決定其特徵㈣和槽縫寬度 不會像微帶線，有_的穿孔，㈣大、 期能提供-種更優質之植人式天線。 積極研究 【發明内容】 8 200952257 緣是： 本發明之主要目的，其係提供一種寬頻共平面波導饋 入之對稱螺旋單極生醫植入式天線，該植入式天線所使用 之基板係為高介電係數高品質因數的微波陶瓷材所製成。 本發明之另一主要目的，其係提供一種寬頻共平面波 導饋入之對稱螺旋單極生醫植入式天線，該天線主要可含 括基板、輻射金屬部、接地平面部與饋入網路；基板可採 用高介電係數（εΓ=25〜35)及品質因數(Qxf=30,000〜50,000) ® 之微波陶瓷基板。 本發明之再一主要目的，其係提供一種寬頻共平面波 導饋入之對稱螺旋單極生醫植入式天線，該植入式天線於 基板上係設有一以共平面波導（CPW)饋入方式設計完成 之天線圖樣（在本文中即是代表天線構造），該天線圖樣 於饋入部軸線兩侧且形成有相對稱之第一及第二螺旋 段，於第一及第二螺旋段中並各自形成有槽縫，於饋入端 兩側並設有第一及第二接地平面部，於第一及第二接地平 〇 面部與饋入部軸線之饋入端並形成有一間隙。 本發明之又一主要目的，其係提供一種寬頻共平面波 導饋入之對稱螺旋單極生醫植入式天線，天線圖樣之接地 平面部與饋入部軸線之饋入端兩者間形成有一間隙，該間 隙可為0.5mm;饋入端之寬度可為1mm;饋入部軸線之 寬度可為2mm ;第一及第二螺旋段之寬度可為1mm ;槽 缝之寬度可為lmm;第一及第二接地平面部之面積相同 可為 6.5mmxlmm。 9 200952257 有關本發明之其他目的及本發明之具體構造，茲佐以 圖式詳加說明如后。 【實施方式】 本發明利用電磁模擬軟體模擬天線之中心頻率、小於 -10dB頻帶之返回損失(Return Loss)、是否符合阻抗匹配 (50Ω)、場型、增益等等的數值分析與設計。由於天線尺 寸是人體通訊設備設計中最重要的考慮事項。利用共平面 ® 波導（coplanar waveguide, CPW)饋入的設計可縮小天線尺 寸。天線圖樣（8) ’其係如第一圖所示者，於圖樣（8)主體 中心具有一饋入部軸線（1)及位於饋入部軸線（1)前端且寬 度較其為小之饋入端（11)，於本發明實施例中之饋入部軸 線（1)的寬度Ws可為2mm，而饋入端（11)之寬度wf可為 1mm ’前述饋入部轴線（1)之另端則分別向兩侧形成相對 稱且為螺旋狀之第一螺旋段(2)及第二螺旋段(3)，前述第 _ 一螺旋段(2 )及第二螺旋段（3 )分別延伸相連續之螺旋子段 (21)(22)(23)(24)(25)/(31)(32)(33)(34)(35)，於螺旋子段 (23)/(33)與饋入部軸線（1)之間形成有一槽縫(41)/(51)，螺 旋段（2)與（3)分別與其螺旋子段（2 1)(22)(23)(24)(25)/ (31)(32)(33)(34)(35)之間並形成有槽縫(42)(43)(44)(45)/ (52) (53)(54)(55)。前述槽縫(41)(42)(43)(44)(45)/(51)(52) (53) (54)(55)之寬度均為相同，且該等槽縫（41)(42)(43) (44)(45)/(5 1)(52)(53)(54)(55)之寬度並與前述螺旋子段 (21)(22)(23)(24)(25)/(31)(32)(33)(34)(35)之寬度相同，於 200952257 本發明實施例中，該等槽縫、螺旋段及其子段等之寬度ti 係以lmm為最佳。前述饋入端之兩側分別設有一間 隙（6)(7)及位於間隙（6)(7)旁侧之第一接地面（81)、第二接 地面（82)，前述間隙（6)(7)之寬度^在本實施例中可為 0.5mm。前述第一接地面（81)及第二接地面（82)之面積 LgxWg係可為3.85x6.5mm2，整個天線面積則可為 W><L(19.35mmxl5mm)。當然，前述天線之饋入部軸線、 螺旋段及其子段、第一接地面及第二接地面均採用導電係 ❹數尚之金屬，譬如：鋼、鋁…等做為材料。本發明利用相 對稱之螺旋段（2)(3)及其螺旋子段（21 )(22)(23)(24)(25)/ (31)(32)(33)(34)(35) ’可產生電感效應且饋入端（u)的線 寬和槽縫(41)(42)(43)(44)(45)/(51)(52)(53)(54)(55)等寬度 可讓本發明天線達到阻抗匹配。本發明之天線圖樣（8)整 體係如第二圖所示之製造步驟被完成在微波陶瓷基板(9) 上，為了防止特定吸收率（SAR)值超過安全範圍，在微波 陶瓷基板（9)上之天線圖樣外表面可覆蓋一層氧化銘 (AI2O3)板（91) ’該氧化銘（Α12〇3)板（91)之介電質常數 sr2=9.8，厚度d=0.4mm。前述微波陶瓷基板（9)厚度 h=lmm ’介電常數srl=25〜35(高介電常數的基板能達到縮 小天線尺寸之目的）’在氧化鋁（Α1ζ〇3)板（91)被覆於微波 陶瓷基板(9)上時之整體狀態則如第三圖所示者。本發明 針對最大電磁波特定吸收率（SAR)值，係計算當天線植入 人體組織時因為電磁波輻射而產生之最大特定吸收率 (SAR)值。對於一個組織每單位質量所吸收的能量，我們 11 200952257 疋義為特又吸收率（Specific Absorption Rate, SAR)利用 電％強度、導電性及質量密度與吸收率的關係，其代表公 式為· 其中’E表示電場強度，單位為（V/m) ; σ代表的是該 組織材質的導電係數(S/m);而ρ則是這個組織的單位密 度(kg/m3) ’也就是單位體積的質量數。特定吸收率（sar) ❾值的安全限制通常是採用平均特定吸收率（SAR)值分佈而 不是觀察一點的特定吸收率（SAR)值。本發明採電磁模擬 軟體（有限元素法）來計算組織中最大之特定吸收率（SAR) 值分部’需特別注意人體組織的建立、並給予組織正確的 介電常數、天線置入適當的組織位子、天線的頻帶必須符 合MICS頻段，在這模擬環境之下進行特定吸收率（SAR) 值模擬如第四圖所示。由電磁模擬軟體所建立的幾何模型 如第四圖所示’將可得到組織體積、面之特定吸收率（SAr) © 值分佈’並且可在組織中給予一條特定吸收率校正線 (SAR Calibration line)，將可由軟體計算出此線的特定吸 收率（SAR)值並可利用曲線圖呈現如第五圖所示。在模擬 時對於組織中給定的質量而言，特定吸收率（SAr)值的體 積可表示成吸收功率，一般定義的組織為1克或1〇克的 平均值(mW/g)。 本發明之天線係為CPW饋入對稱螺旋單極天線，分 為單極和對稱螺旋兩部份，單極天線為χ/2偶極天線的簡 化’因為單極天線利用接地面產生鏡像電流，所以天線長 12 200952257 度=需偶極天線的-半λ/4。本發以線結構經觀察電流 /刀布如第十圖所料算單極部分的波長確實符合單極天 線入/4的特性，其單極天線產生的場形也跟偶極天線相 同。本發明湘天線彎折的方式，亦即形成對稱螺旋狀， :可產生電感效應’另可達到縮小天線尺寸和縮短天線長 度的目的。另方面，利用饋入線的線寬和槽縫寬度可容易 的達到阻抗匹配，是本發明天線結構的優點。 Ο ❹ 本發明依第二圖所示之步驟進行製作‘，本發明採用網 版印刷的方式，將天線圖樣利用繪圖軟體描繪之後，製成 網印版，然後再利用網印機將銀膠印刷在厚度lmm的陶 瓷基板上。印刷完後的樣品放入高溫爐烘烤去除有機物， 為了避免仿人體液滲入天線成品，造成特性不良，因此在 板子四周以及接頭饋入的位置需塗上防水膠，以達到防水 =的。天線面積為19.35xl5mm2。本發明在天線樣品完成 < ，接著使用網路分析儀來進行量測，最後量測的社果並 與模擬相比較。 ^ 人本發明進行人體軟組織量測之實驗，其係利用與人體 ”電常數相近的仿體液替代人體軟組織，其内容成分包含 水、鹽和纖維素等調製而成。下表係在4Q2mh〜 =電常數⑹、傳導率(σ)，天線可在這些仿體環境進 出:以含量測天線的場型、頻寬、工作頻段、平均輸 13 200952257 相對介電係數 導電率 ⑹ (σ, S/m) 眼球組織 57.7 1.00 皮膚 46.7 0.69 肌肉 58.8 0.84 心臟 66.0 0.97 天線植入人體必須符合MICS Band : 402〜405MHz， ® 天線浸入仿體液（ε，46.7，a=0.69S/m在402MHz)實測以 及使用模擬軟體計算的返回損失(return loss)如第六圖所 示。此植入式天線置入仿體液的中心頻率為431MHz與模 擬的中心頻率相差 30MHz。實測頻寬（BW)約 ΙΟΟΜΗζ/25%、返回損失為-43dB，優於模擬頻寬 BW(19%)、返回損失為_4〇dB。 此模擬天線頻率為402MHz所得的輻射場型如第七 ❹ 圖所示。當天線在E plane時主極化面的輻射場型保有單 極天線的特性’而H plane的主極化面則保有全向性的輻 射天線場型特性。此天線的立體增益和增益變化曲線分別 如第八及九圖所示，由圖可知在402MHz頻帶的天線最大 增益約為-28.7dB’頻率從100MHz〜1GHz最高增益與最低 增益相差9dB。 本發明之CPW饋入對稱螺旋單極天線成果如第六圖 之返回損失圖’實測結果之頻寬為100MHz，比例頻寬達 25%，比較模擬的比例頻寬19%更為優異；雖然中心頻率 200952257 沒有模擬的精準，但是此寬頻可以彌補頻率的飄移，符合 MICS頻帶：402〜405MHz。天線增益約為-28dB，Η、E 平面有著單極天線和全向性的輻射場型。組織中之最大特 定吸收率（SAR)值經過適當的功率調整後，已達到符合安 全特定吸收率（SAR)值範圍。 統論之，本發明利用高介電係數高品質因數的微波陶瓷 材料作為天線基板且於基板上採用以共面波導饋入方式 設計之天線圖樣的植入式天線，於基板上之天線圖樣則包 ❹ 含有第一及第二接地平面部、饋入部及二相對稱之第一和 第二螺旋段，藉著此種設計使本發明植入式天線具有可提 高頻寬、結構精簡及面積輕薄短小可更微型化等優點，更 方便植入人體者，本發明顯然具有產業利用價值。 【圖式簡單說明】 第一圖：係本發明天線圖樣構造示意圖。 第二圖：係本發明天線製作之步驟示意圖。 第三圖：係本發明天線基板覆蓋一上層之氧化鋁板的 示意圖。 第四圖：係本發明模擬天線放入軟組織環境中之示意 圖。 第五圖：係本發明模擬特定吸收率校正線（SAR Calibration line)曲線圖。 第六圖：係本發明CPW饋入之對稱螺旋單極天線在組 織中模擬和實測的返回損失反射值的變化 15 200952257 圖。 第七圖：係本發明模擬操作頻率為402MHz之輻射場 型圖。 第八圖：係本發明模擬天線增益曲線圖。 第九圖：係本發明模擬402MHz頻帶立體增益圖。 第十圖：係本發明天線電流分布圖。 【主要元件符號說明】 (1) 饋入部軸線 <11)饋入端 (2) 第一螺旋段 (21)(22)(23)(24)(25)螺旋子段 (3) 第二螺旋段 (31)(32)(33)(34)(35)螺旋子段 (41)(42)(43)(44)(45)槽縫 (51)(52)(53)(54)(55)槽縫 ⑹⑺間隙 (8) 天線圖樣 (81) 第一接地面 (82) 第二接地面 (9) 微波陶瓷基板 (91)氧化銘（Al2〇3)板 16(Ground Plane) and the Feed Network, each part has an impact on the operational characteristics of the antenna. Generally, the antenna structure is changed to achieve the desired characteristics. The antenna is usually selected in terms of material usage. High-metals such as copper, metal, etc. are commonly used for radiating metal sheets and ground planes. The part of the dielectric substrate, the most commonly used substrate is the general FR4, RO substrate. Although it is easy to manufacture, it is often because the dielectric constant of the material is not high, and the reflection loss and bandwidth of the antenna are not good. The size of the line is also difficult. Inventors, in view of the fact that the implanted antenna must be more easily implanted into the human body and can improve the efficiency of the external monitoring system and the antenna, the present invention - reducing the antenna area, low material = transmission architecture 'The antenna pattern material is designed for the CPW feed. The advantage of the frequency f type is that it is easy to combine with the microwave circuit components, and the feeding characteristics are not affected by the substrate thickness variation and the electrical ratio. (4) and the groove The slit width is not like the microstrip line, there are _ perforations, (4) large, period can provide a better quality implantable antenna. Active Research [Invention] 8 200952257 The reason is: The main purpose of the present invention is to provide a symmetric spiral monopole biomedical implant antenna with broadband common-coaxial waveguide feeding, and the substrate used for the implanted antenna is Made of microwave ceramic material with high dielectric constant and high quality factor. Another main object of the present invention is to provide a symmetric spiral monopole biomedical implantable antenna with a wide frequency coplanar waveguide feeding, which mainly includes a substrate, a radiating metal portion, a ground plane portion, and a feed network. The substrate may be a microwave ceramic substrate having a high dielectric constant (εΓ=25 to 35) and a quality factor (Qxf=30,000 to 50,000) ® . A further main object of the present invention is to provide a symmetric spiral monopole biomedical implantable antenna with a wide frequency coplanar waveguide feeding, the implanted antenna being provided with a coplanar waveguide (CPW) feeding on the substrate. The antenna pattern (in this case, representing the antenna structure) is designed in a manner, and the antenna pattern is formed on both sides of the feeding portion axis and is formed with symmetrical first and second spiral segments in the first and second spiral segments. Each of the slots is formed with a first and second ground plane portions on both sides of the feed end, and a gap is formed between the first and second ground plane portions and the feed end of the feed portion axis. Another main object of the present invention is to provide a symmetric spiral monopole biomedical implantable antenna with a wide-band coplanar waveguide feeding, wherein a gap is formed between the ground plane portion of the antenna pattern and the feed end of the feed portion axis. The gap may be 0.5 mm; the width of the feeding end may be 1 mm; the width of the feeding portion axis may be 2 mm; the width of the first and second spiral segments may be 1 mm; the width of the slot may be 1 mm; The area of the second ground plane portion may be 6.5 mm x 1 mm. 9 200952257 The other objects of the present invention and the specific construction of the present invention are described in detail below. [Embodiment] The present invention utilizes an electromagnetic simulation software to simulate a center frequency of an antenna, a return loss of less than -10 dB band, a compliance with impedance matching (50 Ω), a field type, a gain, and the like. Because the antenna size is the most important consideration in the design of human body communication equipment. The use of coplanar waveguide (CPW) feeds reduces the size of the antenna. The antenna pattern (8) is as shown in the first figure, and has a feed-in axis (1) at the center of the main body of the pattern (8) and a feed end located at the front end of the feed-in axis (1) and having a smaller width. (11), the width Ws of the feed portion axis (1) in the embodiment of the present invention may be 2 mm, and the width wf of the feed end (11) may be 1 mm 'the other end of the feed portion axis (1) A first spiral segment (2) and a second spiral segment (3) which are symmetrical and spirally formed are respectively formed on both sides, and the first spiral segment (2) and the second spiral segment (3) are respectively extended in a continuous phase. Spiral subsection (21) (22) (23) (24) (25) / (31) (32) (33) (34) (35), in the helical subsection (23) / (33) and the feed axis (1) A slot (41) / (51) is formed between the spiral segments (2) and (3) and their helical segments (2 1) (22) (23) (24) (25) / (31 ) (32) (33), (34) and (35) are formed with slots (42) (43) (44) (45) / (52) (53) (54) (55). The slits (41) (42) (43) (44) (45) / (51) (52) (53) (54) (55) have the same width, and the slots (41) (42) (43) (44) (45) / (5 1) (52) (53) (54) (55) the width and the aforementioned spiral subsection (21) (22) (23) (24) (25) / (31) (32) (33) (34) (35) The width is the same, in 200952257 In the embodiment of the present invention, the width ti of the slots, the spiral segments and the sub-sections thereof is preferably 1 mm. A gap (6) (7) and a first ground plane (81) and a second ground plane (82) located on the side of the gap (6) (7) are respectively disposed on two sides of the feeding end, and the gap (6) The width of (7) can be 0.5 mm in this embodiment. The area LgxWg of the first ground plane (81) and the second ground plane (82) may be 3.85 x 6.5 mm2, and the entire antenna area may be W > L (19.35 mm x 15 mm). Of course, the feed antenna axis, the spiral segment and its sub-segments, the first ground plane and the second ground plane of the antenna are all made of a conductive metal such as steel, aluminum, or the like. The invention utilizes the symmetrical spiral section (2) (3) and its helical subsection (21) (22) (23) (24) (25) / (31) (32) (33) (34) (35) 'Inductance effect and line width and slot (41) at the feed end (u) (42) (43) (44) (45) / (51) (52) (53) (54) (55), etc. The width allows the antenna of the present invention to achieve impedance matching. The antenna pattern (8) of the present invention is integrally formed on the microwave ceramic substrate (9) as shown in the second figure. In order to prevent the specific absorption rate (SAR) value from exceeding the safe range, the microwave ceramic substrate (9) The outer surface of the antenna pattern can be covered with a layer of oxidized Ming (AI2O3) plate (91). The dielectric constant sr2 = 9.8 and the thickness d = 0.4 mm of the oxide (Α12〇3) plate (91). The microwave ceramic substrate (9) has a thickness h = 1 mm 'dielectric constant srl = 25 to 35 (a substrate having a high dielectric constant can achieve the purpose of reducing the size of the antenna) 'coated on the alumina (Α1ζ〇3) plate (91) The overall state of the microwave ceramic substrate (9) is as shown in the third figure. The present invention is directed to a maximum specific absorption rate (SAR) value of electromagnetic waves, which is a calculation of a maximum specific absorption rate (SAR) value due to electromagnetic wave radiation when an antenna is implanted into a human tissue. For the energy absorbed by a tissue per unit mass, we 11 200952257 Spec 为 又 Specific Absorption Rate (SAR) using the relationship between electric % strength, electrical conductivity and mass density and absorption rate, which is represented by 'E represents the electric field strength in units of (V/m); σ represents the conductivity of the material of the tissue (S/m); and ρ is the unit density of the tissue (kg/m3) 'that is the unit volume Mass number. The safety limit for a specific absorption rate (sar) enthalpy is usually a specific absorption rate (SAR) value that is measured using an average specific absorption rate (SAR) value rather than an observation point. The invention adopts electromagnetic simulation software (finite element method) to calculate the largest specific absorption rate (SAR) value in the tissue. 'Special attention should be paid to the establishment of human tissue, and the correct dielectric constant of the tissue is given, and the antenna is placed in an appropriate tissue. The frequency band of the position and antenna must conform to the MICS band, and the specific absorption rate (SAR) value simulation under this simulation environment is shown in the fourth figure. The geometric model established by the electromagnetic simulation software, as shown in the fourth figure, 'will get the tissue volume, the specific absorption rate of the surface (SAr) © value distribution' and can give a specific absorption rate correction line in the tissue (SAR Calibration line) The specific absorption rate (SAR) value of this line will be calculated by the software and can be represented by the graph as shown in the fifth figure. The volume of a specific absorbance (SAr) value can be expressed as the absorbed power for a given mass in the tissue at the time of simulation, and the generally defined tissue is the average of 1 gram or 1 gram (mW/g). The antenna of the present invention is a CPW fed symmetric spiral monopole antenna, which is divided into two parts: a monopole and a symmetrical spiral. The monopole antenna is a simplified χ/2 dipole antenna because the monopole antenna generates a mirror current by using a ground plane. So the antenna length is 12 200952257 degrees = the half-λ/4 of the dipole antenna is required. The current structure of the wire is observed by the current/knife. As shown in the tenth figure, the wavelength of the unipolar portion is in conformity with the characteristics of the unipolar antenna input /4, and the field shape produced by the monopole antenna is also the same as that of the dipole antenna. The method of bending the Xiang antenna of the present invention, that is, forming a symmetrical spiral shape, can produce an inductance effect, and the purpose of reducing the antenna size and shortening the antenna length can be achieved. On the other hand, impedance matching can be easily achieved by using the line width of the feed line and the slot width, which is an advantage of the antenna structure of the present invention. ❹ ❹ The invention is produced according to the steps shown in the second figure. The invention adopts the method of screen printing, and after the antenna pattern is drawn by the drawing software, the screen printing plate is prepared, and then the silver printing is printed by the screen printing machine. On a ceramic substrate having a thickness of 1 mm. After the printing, the sample is placed in a high-temperature furnace to be baked to remove organic matter. In order to prevent the imitation of human body liquid into the antenna, the characteristics are poor. Therefore, waterproof glue should be applied around the board and the joint feeding position to achieve waterproofing. The antenna area is 19.35xl5mm2. The present invention completes the antenna sample < and then uses a network analyzer to measure, and finally measures the fruit and compares it with the simulation. ^ Human invention The experiment of measuring human soft tissue is carried out by replacing the human soft tissue with a body fluid similar to the human body's electric constant, and the content thereof is composed of water, salt and cellulose. The following table is in 4Q2mh~= Electric constant (6), conductivity (σ), the antenna can enter and exit in these imitation environments: the field type, bandwidth, working frequency band, average transmission of the antenna by the content 13 200952257 Relative dielectric coefficient conductivity (6) (σ, S/m ) Eye tissue 57.7 1.00 Skin 46.7 0.69 Muscle 58.8 0.84 Heart 66.0 0.97 Antenna implanted in the human body must comply with MICS Band: 402~405MHz, ® Antenna immersed in body fluid (ε, 46.7, a=0.69S/m at 402MHz) measured and simulated The software-calculated return loss is shown in Figure 6. The center frequency of the implanted antenna is 431MHz and the simulated center frequency is 30MHz. The measured bandwidth (BW) is about ΙΟΟΜΗζ/25%. The return loss is -43dB, which is better than the analog bandwidth BW (19%) and the return loss is _4〇dB. The radiation field of the analog antenna frequency is 402MHz as shown in the seventh diagram. When the antenna is in the E plane The radiation field of the polarization plane retains the characteristics of the monopole antenna' while the main plane of the H plane maintains the omnidirectional radiation antenna field characteristics. The stereo gain and gain curves of this antenna are shown in Figure 8 and Figure 9, respectively. As shown, it can be seen from the figure that the maximum gain of the antenna in the 402 MHz band is about -28.7 dB'. The frequency is different from the lowest gain by 100 dB from 100 MHz to 1 GHz. The CPW feed symmetric helical monopole antenna of the present invention returns as shown in the sixth figure. The loss graph's measured result has a bandwidth of 100MHz, a proportional bandwidth of 25%, and a comparative analog bandwidth of 19%. Although the center frequency 200952257 has no analog accuracy, this broadband can compensate for the frequency drift and conform to the MICS. Band: 402~405MHz. The antenna gain is about -28dB, and the Η and E planes have a monopole antenna and an omnidirectional radiation pattern. The maximum specific absorption rate (SAR) value in the tissue is adjusted after proper power adjustment. It conforms to the range of safety specific absorption rate (SAR) values. In general, the present invention utilizes a high dielectric constant high quality factor microwave ceramic material as an antenna substrate and is used on a substrate. The implantable antenna of the antenna pattern designed by the surface waveguide feeding method, the antenna pattern on the substrate includes the first and second ground plane portions, the feeding portion and the first and second spiral segments symmetrical, With such a design, the implantable antenna of the present invention has the advantages of improved bandwidth, compact structure, light and thin area, miniaturization, and the like, and is more convenient for implantation into a human body, and the present invention obviously has industrial utilization value. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the structure of an antenna pattern of the present invention. The second figure is a schematic diagram of the steps of fabricating the antenna of the present invention. Fig. 3 is a schematic view showing an antenna substrate of the present invention covering an upper layer of an alumina plate. Fig. 4 is a schematic view showing the insertion of the analog antenna of the present invention into a soft tissue environment. Fifth Figure: This is a simulation of a specific SAR Calibration line. Fig. 6 is a graph showing the variation of the return loss reflection value simulated and measured in the tissue of the symmetric helical monopole antenna fed by the CPW of the present invention 15 200952257 Figure 7 is a radiation pattern diagram of the present invention having a simulated operating frequency of 402 MHz. Figure 8 is a graph showing the gain of the analog antenna of the present invention. Ninth diagram: The present invention simulates a stereo gain diagram of a 402 MHz band. Figure 10 is a diagram showing the antenna current distribution of the present invention. [Description of main component symbols] (1) Feeder axis <11) Feeding end (2) First spiral segment (21) (22) (23) (24) (25) Spiral subsection (3) Second spiral Segment (31) (32) (33) (34) (35) Spiral subsection (41) (42) (43) (44) (45) Slot (51) (52) (53) (54) (55 ) Slot (6) (7) Clearance (8) Antenna pattern (81) First ground plane (82) Second ground plane (9) Microwave ceramic substrate (91) Oxidation (Al2〇3) board 16