What is the gain of a boos費銀ter antenna? That is to say, under the 費關condition of equal input 市服power, the ratio of 那銀the power density of the si現睡gnal generated by the antenna 國靜and the ideal radiating un拿拍it at the same point in space. Of cour的相se, this explanation is a舞著 bit confusing. In layman's姐雪 terms, gain indicates how many tim坐兒es the antenna can amplify the化亮 signal. Here comes the proble物做m again. The booster antenn拍雪a is a passive compo說體nent that does not req車相uire power. How can it be amplified?我空 Isn’t this a violation of the mo學老st basic principle o如吃f conservation of energy?

Of course, there are many ways of 裡花gaining antennas to achieve high gains畫就. Here we talk about the南跳 gain principle of rod antennas commo木國nly used in routing. The scientific nam妹舊e of this kind of antenna is called a s紙聽piral inverter antenna. From a structu輛答ral point of view, it i討都s a hybrid structure of a line如輛ar oscillator and a s對物piral inverter. The linear osc他開illator part is responsible for 妹錢transmitting the signal, and the 妹農spiral inverter is responsi在費ble for changing the phase of the si遠黃gnal, so that the two微月 oscillators emit sig線綠nals with different phases. After t你身his signal is combin路外ed, a signal with a larger amplitude 商她is formed. In this wa訊金y, The signal is enha視校nced.

However, after the signal i愛相s combined, the radiation門房 angle of the beam will become 腦雨smaller. As a rod antenna,線要 although the radial signal i業內s still covered by 3看機60 degrees, the axial coverage ang讀我le is greatly reduced. That is t北訊o say, the coverage of the rod-shape醫厭d high-gain antenna does 錯訊not change. (In fact, after multipl河明e phase inversions and attenuations, t答月he attenuation of the signal on the a窗資ntenna will reduce its transmission fu到到nction). This is the principle of ener小這gy conservation. Decided, but it i從雪s equivalent to thinning the ent醫鐘ire signal. In this way, th快事e signal coverage is increased, but t很資he coverage height i腦上s reduced.