Background technology
Cavity body filter is widely used in the communications field as a kind of frequency selection device, especially field of radio frequency communication.In the base station, filter is used for selecting signal of communication, clutter or interference signal that the filtering communication signal frequency is outer.
Cavity body filter generally comprises three classes, and the first kind is coaxial cavity filter, and second class is dielectric filter, and the 3rd class is waveguide filter.
Existing dielectric filter has various modes, wherein the dielectric filter of horizontal magnetic (TM) pattern is in order to guarantee its magnetic field model and parameter index, need the upper surface of medium resonant rod and the gap of resonant cavity end face to remain on controlled scope, if it is excessive that the gap changes, will have a strong impact on radio-frequency (RF) index.As shown in Figure 1, being the structural representation of prior art dielectric filter, is that example describes with a single chamber only among the figure:
Dielectric filter of the prior art comprises: cavity 110, cover plate 120 and medium resonant rod 130, the lower surface of medium resonant rod lower end 130 lower surface resonant cavity welds together, medium resonant rod upper surface resonant cavity end face (cover plate bottom surface) leaves gap h1, but because the thermal coefficient of expansion between medium resonant rod 130 and the metallic cavity 110 differs bigger, in case temperature raises, the height of metallic cavity 110 increases bigger, and the increase of medium resonant rod height is less, the gap of medium resonant rod upper surface resonant cavity end face (cover plate bottom surface) increases to the h2 (not shown), has had a strong impact on radio-frequency (RF) index.
Summary of the invention
The technical problem that the present invention solves provides dielectric filter, medium resonant rod mounting structure and communication equipment, can improve the stability indicator of dielectric filter, makes that the mounting structure of dielectric resonator is more reliable.
A kind of dielectric filter that the embodiment of the invention provides, comprise: cavity, cover plate and be installed on medium resonant rod in the cavity, the described cavity of described cover plate capping forms resonant cavity, it is characterized in that, is provided with the non-metallic support for control gap between described medium resonant rod and the cover plate.
A kind of medium resonant rod mounting structure that the embodiment of the invention provides, comprise: cavity, cover plate and be installed on medium resonant rod in the cavity, the described cavity of described cover plate capping forms resonant cavity, it is characterized in that, be provided with the non-metallic support for control gap between described medium resonant rod and the cover plate.
A kind of communication equipment comprises above-mentioned dielectric filter, and described cavity body filter is located at the transceiver circuit part of described communication equipment, is used for signal frequency is selected.
The dielectric filter that the embodiment of the invention provides and the mounting structure of medium resonant rod thereof, between medium resonant rod and cover plate, be provided with the non-metallic support for control gap, make when temperature changes, gap between medium resonant rod and the cover plate is in controlled scope, when having solved owing to variations in temperature, gap between medium resonant rod and the cover plate changes the excessive problem that causes dielectric filter radio-frequency (RF) index shakiness, improves the stability of dielectric filter greatly.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that obtains under the creative work prerequisite.
The inventor finds in to the practice of prior art and research process, in order to guarantee the parameter of TM mould dielectric filter, when between medium resonant rod and the resonant cavity surface and imprecision contact, but maintenance certain clearance, as long as this gap is less than certain value, can guarantee that equally dielectric filter works under the TM pattern, if gap length changes simultaneously, then can further guarantee dielectric filter radio-frequency (RF) index parameter in very among a small circle.
Therefore, the inventor provides increases nonmetal distance piece between medium resonant rod and cover plate, realize the controlled of gap by nonmetal distance piece, and then guaranteed dielectric filter radio-frequency (RF) index parameter.
Embodiment one, a kind of dielectric filter, structural representation (is that example describes with a single chamber only among the figure as shown in Figure 2, concrete accompanying drawing structure is not construed as limiting the invention), comprise: cavity 210, cover plate 220 and be installed on medium resonant rod 230 in the cavity 210, the described cavity 210 of described cover plate 220 cappings forms resonant cavity, is provided with the non-metallic support 240 for control gap between described medium resonant rod 230 and the cover plate 220.When cover plate being carried out the material selection, described cover plate can select to have certain flexible metal material, can certainly be on the basis of the existing aluminium sheet cover plate that adopts usually, suitably the thickness that reduces cover plate is realized its spring function, selection those skilled in the art of concrete cover plate materials can select according to general knowledge, are not construed as limiting the invention.After medium resonant rod assembles, described cover plate by described strutting piece jack-up deformation is taken place with the medium resonant rod correspondence position, form the projection of arc.
When specific implementation, during the dielectric filter assembling, the height H 1 at non-metallic support top is slightly larger than the height H 2 of resonant cavity end face, and described cover plate and medium resonant rod correspondence position by described strutting piece jack-up deformation are taken place, and form the projection of arc.Certainly use non-metallic support can also take other frame modes to realize that concrete implementation is not construed as limiting the invention cover plate jack-up.
For example: can concave station be set in the cover plate position relative with strutting piece, concave station is used for strutting piece is positioned, under this structure under the pattern, then need the height H 1 at non-metallic support top to be slightly larger than the height of concave station bottom surface on the cover plate, to realize non-metallic support cover plate jack-up is formed projection.
When temperature rises, housing depth raises (in this example, because the medium resonant rod expansion rate is subjected to variations in temperature less, therefore main consideration cavity is subjected to Temperature Influence), the deformation of cover plate diminishes, the radian of described arc-shaped protrusions diminishes, and described arc-shaped protrusions tip position descends and forms being the covering that housing depth raises, and makes gap H between described resonant rod and the described cover plate in controlled range.When specifically carrying out the filter design, also can design when temperature rises to the maximum temperature of permission, housing depth rises and to make that elastic pressure between the non-metallic support cavity is 0 critical value, also can when rising to the maximum temperature of permission, temperature still keep certain elastic pressure between the non-metallic support cavity.
When temperature descends, housing depth descends (in this example, because the medium resonant rod expansion rate is subjected to variations in temperature less, therefore main consideration cavity is subjected to Temperature Influence), it is big that cover plate deformation becomes, and housing depth reduces, by the elasticity of cover plate, and the non-metallic support interval action, make gap H (greater than the thickness of non-metallic support) between described resonant rod and the described cover plate in controlled range.When carrying out cavity design, also can change the cross section size of metallic supports simultaneously, under the control different temperatures, the radian of arc-shaped protrusions.
When specific design, described non-metallic support can be designed to toroidal, the tuning screw that the middle part through hole is used for cavity body filter passes.
For better implementation structure location, the diameter of section of described non-metallic support can also be designed to be slightly larger than the medium resonant rod diameter of section, the contact jaw of described non-metallic support and medium resonant rod is provided with medium resonant rod is carried out the spacing groove of circumference.
Be appreciated that, in the embodiment of the invention, the material of described non-metallic support can be materials such as polytetrafluoroethylene (PTFE), according to the needs of product design, for consistency and elasticity can also be selected other non-metallic materials such as bakelite (phenolic plastics), high-strength rubber etc.
The dielectric filter that the embodiment of the invention one provides is provided with the non-metallic support for control gap between medium resonant rod and cover plate, make when temperature changes by strutting piece, gap between medium resonant rod and the cover plate is in controlled scope, when having solved owing to variations in temperature, gap between medium resonant rod and the cover plate changes the excessive problem that causes dielectric filter radio-frequency (RF) index shakiness, improves the stability of dielectric filter greatly.
Embodiment two, a kind of medium resonant rod mounting structure, comprise: cavity, cover plate and be installed on medium resonant rod in the cavity, the described cavity of described cover plate capping forms resonant cavity, is provided with the non-metallic support for control gap between described medium resonant rod and the cover plate.When specific implementation, can have elasticity by described cover plate, after the dielectric filter assembling, under the normal temperature, the height at non-metallic support top is slightly larger than the height of resonant cavity end face, and described cover plate and medium resonant rod correspondence position by described strutting piece jack-up deformation are taken place, and forms the projection of arc.
The diameter of section of described non-metallic support is slightly larger than the medium resonant rod diameter of section, and the contact jaw of described non-metallic support and medium resonant rod is provided with medium resonant rod is carried out the spacing groove of circumference.
Embodiment three, a kind of communication equipment,, comprise the dielectric filter that claim is above-mentioned, described cavity body filter is located at the transceiver circuit part of described communication equipment, is used for signal frequency is selected.
Concrete, described communication equipment can also be application class communication equipments such as base station, tower amplifier for communication equipments such as duplexer, single multiplexer, splitter or mixers.
More than dielectric filter, medium resonant rod mounting structure and communication equipment that the embodiment of the invention is provided be described in detail, wherein:
The dielectric filter that the embodiment of the invention provides and the mounting structure of medium resonant rod thereof, between medium resonant rod and cover plate, be provided with the non-metallic support for control gap, make when temperature changes, gap between medium resonant rod and the cover plate that is to say in controlled scope, no matter normal temperature, high temperature, low temperature is all because the position-limiting action of strutting piece remains in the scope that can control the gap between medium resonant rod and the cover plate.When having solved owing to variations in temperature, the gap between medium resonant rod and the cover plate changes the excessive problem that causes dielectric filter radio-frequency (RF) index shakiness, improves the stability of dielectric filter greatly.Used specific case herein principle of the present invention and execution mode are set forth, the explanation of above embodiment just is used for helping to understand method of the present invention and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present invention, the part that all can change in specific embodiments and applications, in sum, this description should not be construed as limitation of the present invention.