΢��g(sh��)��

��r�g��2008-04-09 15:11 ��Դ��ɖ|��h(hu��n)��޹�˾ ��: ��x��7766

1,��΢��g(sh��)ԭ��

        ΢��g(sh��)��һ�T��Ҫ�߶Ȍ�򞼼�ܵČ��I(y��)��g(sh��)֪�R,��΢��g(sh��)��Փ��A(ch��)�ǽ�(j��ng)��늴ň��Փ��Ŀ��(bi��o)�ǽ�Q΢��(y��ng)�ù��еČ��H��},��΢��һ�T��Փ�c��`��нY(ji��)�ϵ�һ�T֪�R,��΢��g(sh��)��Փ�ĳ��l(f��)�c��˹�S��̽M,��˹�S��̽M��ǏČ��`�Кw�{��Y(ji��)��,��(sh��)΢��H��(y��ng)�õĹ��̆��}��ͨ�^��ՓӋ��õ��_�Ľ��,��о�΢��̆��}�r��˱��_һЩ��(f��)�s�Ĕ�(sh��)�W(xu��)�\��͟o��Ć��},�� Ҫ��(j��)��w��r��һЩ����о��Ć��}��,��Ч��̎��,��ͨ�^��`��Փ��Y(ji��)��ÿ��΢��̼��g(sh��)�ˆT�߂�Ļ��,��

2��΢��x

        ΢��һ�N�l�ʷǳ��ߵ�늴Ų�,��΢��Ĳ��L��]��_�Ľ��,��һ��ָ��ײ��ײ��ͺ��ײ��,��Ҳ��ǲ��L��1mm��1m��ҵ�늴Ų�,��΢��l�ʺܸߣ��Ҳ�г��l늴Ų�,��

        ��M(j��n)�б��^,��@�΢��I(y��)��늺͟o��в��V��l��c��L��ڱ��,��

	�l��	��L
��I(y��)��	50Hz ��60Hz	60000000��50000000m
�o��в��V��	300--3000KHz	1000--100m
΢��	300--300000MHz	1--0.001m

��ϵ�y(t��ng)��l��c��L��

��΢��đ�(y��ng)�ØO��V��,��˱��໥�ĸɔ_��I(y��),��ƌW(xu��)��t(y��)�W(xu��)ʹ�õ�΢��l��ǲ�ͬ��,��F(xi��n)��ڱ��

�l�ʷ��/MHz	��	��Ĳ��L/m	��l��/MHz	��L/m
890��940	L	0.330	915±25	0.328
2400��2500	S	0.122	2450±50	0.122
5725��5875	C	0.052	5800±	0.052
22000��22250	K	0.014	22125±	0.014

��΢��l�ʷ��

        ��ͬ��l�ʵ�΢��ϵ�y(t��ng)��в�ͬ�ļ��g(sh��)��ԡ��a(ch��n)�ɱ��;,��΢��ϵ�y(t��ng)�Ĺ��l��Խ��,��Y(ji��)��(g��u)�ߴ��ԽС,��΢��ͨӍϵ�y(t��ng)�Ĺ��l��Խ��,��Ϣ��Խ��΢��_(d��)ϵ�y(t��ng)�Ĺ��l��Խ��,��_(d��)��̖�ķ��Ժ�ϵ�y(t��ng)�ķֱ��ʾ�Խ��,��΢��l��Խ�ߣ��ݔ�͂�ݔ��ݔ?sh��)ēp�ľ�Խ��,��

        Ŀǰ��(n��i)ֻ��915MHz��2450MHz ��V��ʹ��,��^�ߵăɂ��l�ʶ�߀�]�к��m�Ĵ��ʹ��I(y��)�O(sh��)�䡣

3��΢��|(zh��)

        ΢��늴Ų�,��늴Ų��T�練��,��͸��桢��,��ƫ��Լ��S��늴Ų��ݔ?sh��)Ȳ��,��@�͛Q��΢��Įa(ch��n)��ݔ,��Ŵ�,��ݗ��Ȇ��}��ͬ��ͨ�ğo��늡��,��΢��ϵ�y(t��ng)��,��M��|(zh��)��J(r��n)��Ǽ��ģ�΢��ϵ�y(t��ng)�]�Ќ�(d��o)��ʽ�·,��,��ֱ��늵Ă�ݔ��ԅ��(sh��)�Լ��ݺ�늸еȸ��ʧȥ��_�е��x��΢��I(l��ng)��,��ͨ��(y��ng)��^“��”�ĸ��ϵ�y(t��ng)��(n��i)늴Ų��ĽY(ji��)��(g��u),��ù��ʡ��l��,��迹,��v��΢��y��Ļ��

        ��w��f��

        3.1.��о�΢��}�r,��(y��ng)ʹ��늴ň��ĸ��,��S��l��׃늴ň��Ч��(y��ng)��ܺ��,��΢��Ĳ��L��·��ֱ��ͬһ��(sh��)��,��λ��F(xi��n)��ʮ��@��@һ�c��횼��Կ��],��

        3.2.΢��r��ֱ��,��ٱ��挢�l(f��)��䣬�䷴�䷽��Ϲ�ķ��Ҏ(gu��)��,��

        3.3.΢��l�ʺܸ�,��ݗ��Ч��(y��ng)��@��ζ��΢��ͨ�Č�(d��o)��ς�ݔ�r,��S��܇��gݗ��,��ӂ�ݔ��ܿ��˥�p��Ԍ��ݔ�M��Ҫ��,��

        3.4.��(d��ng)��䲨�c ��䲨��ӕr��γɲ��ĸ��F(xi��n)��,��а��v��F(xi��n)��΢��(d��o)��C��ǻ�У��҂�Ҳ��ö�Nģʽ��늴ň��ķֲ�,��Ӂ��늴ň��ֲ��ľ��,��

        3.5.΢��Ŀ��g�ֲ�ͬһ��늴ň��һ�ӣ��п��g�ֲ��|(zh��),��늴ň�,��ʹ��΢��ݔ��ϵĿ��gĳ�c,��늈��Ĕ�(sh��)ֵ��С�cԓ̎��g��늈��ȵĶ��η��P(gu��n),��΢��늴ň��g�c��늴ň��Ŀ��͡�

4,��΢��c��ϵ��໥��

        ��(d��ng)΢��ڂ�ݔ�^��ͬ��ϕr,��a(ch��n)��䡢��պʹ�͸�F(xi��n)��,��@Щ��ú��̶�,��Ч��ȡ�Q�ڲ��ϱ��Ďׂ��Ҫ�Ĺ��ԣ��늳��(sh��)��|(zh��)�p�Ľ��У�tgδ,��Q��|(zh��)�p�ģ�,��ȟᡢ�Π�,��ˮ��Ĵ�С��,��

        4.1�� ò��

        ��΢��ӹ�ϵ�y(t��ng)��,��õĲ��Ќ�(d��o)�w,��^��w��|(zh��),��O�Ժʹ��Ի��,��

        4.1.1��(d��o)�w һ��ϵČ�(d��o)�w��~,��y,��X֮Ľ��٣��܉��΢��,��΢��ϵ�y(t��ng)��,��Ì�(d��o)�w��΢��@�N��ʽ��΢��΢��b��г��õĲ��(d��o)��,��Ǿ��λ�A�εĽ��ٹ�,��ͨ��X��S�~�Ƴɡ��w��(d��o)�⾀һ��,��΢��ͨ·,��

        4.1.2�^��w ��΢��ϵ�y(t��ng)�У��^��w��ȫ��ͬ��ͨ�·�еĵ�λ��^��w��͸�^΢��,��յ�΢��ʺ�С,��΢��ͽ^��w�໥�g��Ӱ푣��⾀�Ͳ��P(gu��n)ϵһ��,��ʹ�⾀��ֵط��,��󲿷քt͸�^��ֻ�к��ٲ��ֱ��,��΢��ϵ�y(t��ng)��,��(j��)��ͬ��rʹ��մ�,��ķ��ϩ,��۱�ϩ��֮Ľ^��w��鷴��(y��ng)��Ĳ��,��@�N“͸��”��,��΢��Ҳ��ý^��w��ρ��ֹ��M(j��n)��ĳЩҪ��λ��@�r�Ľ^��w�ͳɞ��Ч��,��

        4.1.3��|(zh��) ��΢��,��|(zh��)��ա��͸�ͷ��,��|(zh��)ͨ��Ǳ��ӹ��,��ͬ�̶ȵ��΢��@��Ҳ�Q��кĽ��|(zh��),��؄e�Ǻ�ˮ�ͺ�֬��ʳƷ,��ͬ�̶ȵ��΢��D(zhu��n)׃?y��u)��ˮ̎��,��ˮ�еĸ��N�ɷֺ��ӄ��ǽ��|(zh��),��

        4.1.4�O�Ժʹ��Ի��   �@��ϵ�һ��ܷǳ��|(zh��)��ϣ�Ҳ��,��պʹ�͸΢��,��(y��ng)��(d��ng)ָ��,��΢��܌��|(zh��)��Ϻ��ИO��,��ԵĲ��Ϯa(ch��n)��Ӱ푵�늈��ʹň��S��O�Ի��,��Բ��ͬ��|(zh��)��һ��,��Ҳ��΢��ӹ��ϡ�

        4.2΢��|(zh��)�Ĵ�͸��|(zh��)

        ΢��M(j��n)��Ϻ�,��΢��ܲ��D(zhu��n)׃?y��u)��,��΢��Ĉ��͹��ʾͲ��ر�˥�p��΢��͸��Ϻ��M(j��n)��˥�p��B(t��i)��ͬ��ό�΢��ܵ��˥�p��ǲ�ͬ��,��@�S��ϵĽ��Զ��,��˥�p��B(t��i)�Q��΢��|(zh��)�Ĵ�͸��

        A,��B͸��ȣ��͸��ȣ� ��(d��ng)΢��M(j��n)��ϕr,��ϱ��ܶ��ģ��S��΢��σ�(n��i)��ĝB͸,��ָ��(sh��)˥�p,��ͬ�r΢��ጷŽo��ϡ��B͸��ȿɱ�ʾ��ό�΢��ܵ�˥�p��Ĵ�С,��һ��ЃɷN��x��

        �� B͸��Ȟ�΢��ʏ��ϱ��p��ֵ��1/e(36.8%)�r�ľ��x,��DE��ʾ��e��Ȼ��(sh��)��ֵ,��

DE=λ0/π gδ

ʽ��λ0-------- ��ɿ��g��L,��

ε---------��늳��(sh��)��

tgδ-------��|(zh��)�p��,��

��΢��ʏ��ϱ��˥�p��ֵ��1/2�r�ľ��x,��^�빦�ʝB͸��D1/2��_(d��)ʽ��

        �B͸��S��L��׃��,��Q��֮,��c�l��P(gu��n)��l��Խ��,��LԽ��,��䴩͸��ҲԽ��915MHz�r��ӵ�20cm;2450MHz�r,��΢��ڿ՚��еĝB͸��Ȟ�12.2cm;915Mhz�r��33.3cm,��

        ΢��B͸��c��ʹ�õĲ��L��ͬһ��(sh��)��,�@Щ�Y(ji��)ՓҲ��ʾ��һ��늴ň��͸��. �ɴ˿�Ҋ,Ŀǰ�h(yu��n)�t�⾀�ӟ᳣�õĲ��L�H��ʮ�ׂ��{��,��,�c�t��,�h(yu��n)�t�⾀�ӟ��,΢��|(zh��)��ϵĴ�͸��Ҫ��Ķࡣ

        ��͸��ļӟ᷽ʽ,��ֻ��M(j��n)�б�Ӽӟ�,��ϵļӟ��r��,�ٟ��(d��o)�ӟ᷶��.��΢��͸��^��c,��σ�(n��i)��ӟ�,��ʹ��ϱ��׺�ͬ�r��γ��w��B(t��i)�ӟᣬ��ӟ᷽ʽ�@Ȼ�Єe�ڟ��(d��o)�ӟ�,��ɴ�,��΢��ӹ��ˇ��һϵ�в�ͬ�ļӟ�Ч��

        B,��΢��ĝB͸��Ҳ��|(zh��)�Ĝض��P(gu��n),��Ҋ�±�

��	�ضȣ��棩	�B͸��ȣ�cm��
��	�ضȣ��棩	915MHz	2450MHz
��	��12	180	70
ˮ	1.5 5.0 15 25 35 45 55 65 75 85 95	4.1 4.8 6.6 9.0 12 13.8 16.3 19 21.5 25 29.5	0.6 0.7 0.9 1.3 1.8 2.0 2.3 2.8 3.2 4.0 4.8