三节3dB带状线耦合器的物理实现Lumped-element quadrature hybrids for wide-band antenna-feed networks.pdfVIP

113.5 LUMPED-ELEMENT QUADRATURE HYBRIDS FOR WIDE- BAND ANTENNA- FEED NETWORKS R. A. De L i l l o AIL Systems Inc. Deer Park, New York 11729 Antenna-feed networks often require coupled-1 ine phase s h i f t sections and quadrature hybrid couplers. Lumped-element devices have been used f o r these purposes when size i s an issue, espe- c i a l l y a t lower frequencies and when the feed network must be compatible w i t h M I M I C technology. Lumped-element approaches also provide a broader range o f coupling values, allowing f o r f l e x i - b i l i t y i n the design of multisection couplers f o r broad bandwidth applications. A new procedure f o r design o f such couplers i s presented i n t h i s paper. The procedure enables the design o f multisection and tandem couplers o f specifiable bandwidth and ripple. Computed performance o f two couplers designed w i t h the new procedure i s presented. GENERAL METHODOLOGY The basis f o r the new design procedure i s a combination o f two previously published concepts. The f i r s t concept i s t h a t a coupl e r having the same performance as two coupled quarter-wave- length transmission lines, i.e. , an electromagnetic (EM) coupler, can be b u i l t a