The circulator also includes a magnet on {HEAD ~ first surface} of the substrate over a resonator circuit connecting the microstrip lines and a pole piece on the second surface of the substrate beneath the ground to provide magnetic bias to {TAIL ~ the substrate} 
The circulator also includes a magnet on { HEAD ~ first surface } of the substrate over a resonator circuit connecting the microstrip lines and a pole piece on the second surface of the substrate beneath the ground to provide magnetic bias to { TAIL ~ the substrate }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL