(19)
(11) EP 0 738 021 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.03.1998 Bulletin 1998/10

(43) Date of publication A2:
16.10.1996 Bulletin 1996/42

(21) Application number: 96105629.8

(22) Date of filing: 10.04.1996
(51) International Patent Classification (IPC)6: H01P 1/20, H01P 1/30
(84) Designated Contracting States:
DE FR GB NL SE

(30) Priority: 11.04.1995 JP 85708/95
18.04.1995 JP 92584/95
26.05.1995 JP 127712/95
02.06.1995 JP 136525/95
02.06.1995 JP 136526/95

(71) Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD
Kadoma-shi, Osaka 571 (JP)

(72) Inventors:
  • Sakai, Masahiro
    Neyagawa-shi, Osaka 572 (JP)
  • Higashino, Hidetaka
    Souraku-gun, Kyoto 619-02 (JP)
  • Setsune, Kentaro
    Sakai-shi, Osaka 590-01 (JP)

(74) Representative: VOSSIUS & PARTNER 
Siebertstrasse 4
81675 München
81675 München (DE)

   


(54) Wireless communication filter operating at low temperature


(57) A high power filter apparatus which is used in a mobile communication base station or the like is provided wherein the temperature stability and frequency selection are excellent, an insertion loss is small, the size is small, power consumption is low and costs are low. A shield case block (1) comprises signal input and output portions (2a) and (2b), and a plurality of closed spaces (10) which house a filter element (11) connected between the signal input and output portions (2a) and (2b). A cooling plate (3) is provided in a heat insulating container (4) which houses the shield case block (1). The shield case block (1) is fixed to the cooling plate (3) in the thermal contact state. Each filter element (11) is placed almost in parallel. A cylindrical hole having an axis which is almost parallel with the face of the filter element (11) penetrates the shield case block (1). A ground rod made of a conductor which changes the volume of the closed space (10) is provided on the inner end portion of a movable member which moves in the axial direction of the cylindrical hole.






Search report