Design of 10dB Directional Coupler using Lumped Elements

Kindly suggest a design for a Directional Coupler using Lumped Elements L, C

Specifications are

Coupling 10dB
Insertion Loss <0.5dB
Return Loss >20dB
Isolation 30dB
Ripple in the coupler < 0.5dB over the entire band, min to max.

Frequency Range -
Option1: 100MHz-200 MHz; fc - 150MHz
Option2: 30 MHz to 512MHz; fc - 270MHz

Kindly suggest with posssible ideas, texts, links, or designs.

Thanks.

U can ger design in Book" Lumperd Element ciruit design" By Inder Bahl.

I think you need to look for book with transmission line transformer technique to find solution. Use lump component to make a distributed circuit equivalent will be not useful for your spec. The bandwidth is too wide.

Wideband Directional Couplers are realized with ferrite cores with copper wires at those frequencies.
For more information, search internet.