4391A 射(she)頻功(gong)(gong)(gong)率計(ji)在設備正常運行期(qi)間(jian)沿(yan)正向或反(fan)射(she)方(fang)向監測峰值脈沖(chong)功(gong)(gong)(gong)率、峰值包絡功(gong)(gong)(gong)率或 CW 功(gong)(gong)(gong)率。設計(ji)用于空中(zhong)導(dao)航設備 DME、ATC 和其他脈沖(chong)射(she)頻系(xi)統,如(ru)遙測、雷達、指揮和控制等。它(ta)們不需要衰減器、定向耦(ou)合器或圖表。