{HEAD ~ The novel circulator} includes a substrate, a predetermined number of microstrip lines disposed on a top of the substrate, a ground layer and a predetermined number of electrical contacts disposed on the bottom of the substrate, and {TAIL ~ a mechanism} for coupling each microstrip line to one of the electrical contacts 
includes
{ HEAD ~ The novel circulator } includes a substrate , a predetermined number of microstrip lines disposed on a top of the substrate , a ground layer and a predetermined number of electrical contacts disposed on the bottom of the substrate , and { TAIL ~ a mechanism } for coupling each microstrip line to one of the electrical contacts
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