HIGH-VOLTAGE ALIGNING REED SWITCH Russian patent published in 2004 - IPC

FIELD: electrical engineering; magnetically operated sealed switches for radio equipment.

SUBSTANCE: proposed reed switch designed for use in radio equipment and for aligning coaxial cables having wave impedance of 75 or 50 Ohms characterized in high-quality alignment at frequencies over 500 MHz has cylindrical glass or ceramic envelope with two ferromagnetic contact members hermetically sealed at their butt-ends and copper-plated throughout entire length, with electroplated noble metal coating on ends of contact members forming gap in overlap offset toward one of envelope butt-ends; envelope is disposed at open end of coaxial cable to ensure electric contact between ends of cable central conductor and round terminals of reed switch; alignment of cable lengths in frequency band of 100 - 5000 MHz governed by voltage standing-wave ratio upon closure of reed switch contact members is restricted by limits of inequality 1 < VSWR < 1.15. Contact members of reed switch are made of wire whose diameter equals that of coaxial cable central conductor; they are partially flattened on one end in vicinity of overlap and welded within envelope so as to minimize relative misalignment between longitudinal axis of each contact member and that of envelope; in this case following relationships should be satisfied between diameter d, flattening length l at bevel angle α⁰, with flattening thickness h and overlap a of reed switch contact members: 0.4 < h/d ≤ 0.5; 0.7 < a/d ≤ 1; 0.5 < a/l ≤ 0.8 at acute angle (90^o - α^o) between mating plane from contacting surface to contact member diameter and longitudinal axis of contact member confined within 45^o < (90^o - α^o) ≤ 60^o. Gap in open reed switch is limited by ratio of coaxial cable section capacitance for reed switch in open state Cop to that for reed switch in closed state Ccl ranging within 0.55 < Cop/Ccl ≤ 0.75, with cable section length being equal to length of reed switch, including its terminals, so as to ensure isolation of minimum 10 dB afforded by open reed switch at high value of frequency band.

EFFECT: enlarged frequency band at desired alignment of high-frequency channels; improved quality of alignment at higher frequencies.

1 cl, 5 dwg