1. A multi-antenna structure including:
a base plate having a grounded metal surface, the grounded metal surface having two short sides and two long sides;
a first antenna arranged on the base plate and arranged on one of the short sides;
a second antenna arranged on the base plate and arranged on the other short side;
a first metal line electrically connected to one of the short sides; and
a second metal line electrically connected to the other short side,
wherein a current path of the two short sides is prolonged because of the first metal line and the second metal line; a longitudinal current is equal to a transverse current at a low frequency; whereby a current of the first antenna and a current of the second antenna does not interfere each other; isolation between the first antenna and the second antenna is improved;
wherein the base plate is a printed circuit board; the base plate includes a first signal feed line and a second signal feed line; the two short sides of the base plate are an upper short side and a lower short side: the two long sides of the base plate are a right long side and a left long side;
wherein the first antenna includes a first rack; the first rack includes a first radiator having a plurality of metal lines; the first radiator is electrically connected to the first signal feed line; the first signal feed line is electrically connected to a coaxial cable;
wherein the second antenna includes a second rack; the sewn rack includes a second radiator having a plurality of metal lines; the second radiator is electrically connected to the second signal feed line; the second signal feed line is electrically connected to a coaxial cable;
wherein the first metal line is electrically connected to the upper short side of the grounded metal surface and is reeled on the first rack of the first antenna or is pasted on a casing of an electronic device;
wherein a length of the first metal line plus a length of the upper short side of the grounded metal surface is between one-half and one-eighth wavelength of a center frequency of the low frequency.
2. The multi-antenna structure in claim 1, wherein the length of the first metal line plus the length of the upper short side of the grounded metal surface is one-quarter wavelength of the center frequency of the low frequency.
3. The multi-antenna structure in claim 2, wherein the second metal line is electrically connected to the lower short side of the grounded metal surface and is reeled on the second rack of the second antenna or is pasted on the casing of the electronic device.
4. The multi-antenna structure in claim 3, wherein a length of the second metal line plus a length of the lower short side of the grounded metal surface is between one-half and one-eighth wavelength of the center frequency of the low frequency.
5. The multi-antenna structure in claim 4, wherein the length of the second metal line plus the length of the lower short side of the grounded metal surface is one-quarter wavelength of the center frequency of the low frequency.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A nozzle for providing carbon dioxide for cleaning, comprising:
a reservoir for receiving liquid carbon dioxide;
a barrel defining a passageway therethrough, the passageway extending to an outlet of the barrel, an internal diameter of the passageway being smaller than an internal diameter of the reservoir;
an orifice effecting fluid communication between the reservoir and the passageway, and through which the liquid carbon dioxide flows to phase transfer into gaseous carbon dioxide and carbon dioxide pellets in the passageway;
a screen member constructed and arranged for interrupting flow of the carbon dioxide pellets greater than a select size from being emitted from the passageway of the barrel; and
the barrel further comprises a plurality of apertures extending therethrough a wall of the barrel.
2. The nozzle of claim 1, wherein the screen member is disposed in the passageway.
3. The nozzle of claim 1, wherein the screen member is disposed at the outlet of the barrel.
4. The nozzle of claim 1, wherein the screen member comprises a plurality of elongated slots extending therethrough.
5. The nozzle of claim 4, wherein the plurality of elongated slots are of different lengths.
6. The nozzle of claim 1, wherein the screen member comprises a plurality of channels extending therethrough.
7. The nozzle of claim 6, wherein at least one of the plurality of channels has a size different than others of the plurality of channels.
8. The nozzle of claim 1, wherein the screen member comprises a collar portion mountable to the barrel at the outlet.
9. The nozzle of claim 8, wherein the collar portion is removably mountable to the barrel at the outlet.
10. The nozzle of claim 1, further comprising: an electrical insulator mounted to the barrel; and
a voltage source connected to the screen member for actuation to mitigate electro-static charges of the carbon dioxide pellets.
11. The nozzle of claim 1, wherein each one of the plurality of apertures having a first end open at the passageway and angled toward the orifice, and a second end opposite the first end and open to an exterior of the barrel, the plurality of apertures venting at least a portion of the gaseous carbon dioxide from the passageway.
12. The nozzle of claim 11, wherein the screen member is mounted to the outlet of the barrel downstream from the plurality of apertures.
13. The nozzle of claim 11, wherein the orifice comprises an outwardly concave surface proximate the passageway.
14. The nozzle of claim 11, further comprising an electrical insulator mounted to the barrel and a voltage source connected to the screen member for actuation to mitigate electro-static charges of the carbon dioxide pellets.
15. The nozzle of claim 1, wherein the reservoir comprises a diameter which is reduced in size closer to the orifice.
16. A nozzle for providing carbon dioxide for cleaning, comprising:
a housing having an outlet;
a reservoir for liquid carbon dioxide within the housing, an internal diameter of the outlet being smaller than an internal diameter of the reservoir, the reservoir being in communication with the outlet and having a reduced diameter approaching the outlet for facilitating the phase transfer of the liquid carbon dioxide into gaseous carbon dioxide and carbon dioxide pellets; and
a screen member disposed downstream in a direction of carbon dioxide flow from the outlet for interrupting flow of carbon dioxide pellets greater than a select size from being emitted from the screen member.
17. The nozzle of claim 16, wherein the screen member is removably mountable to the housing at the outlet.
18. The nozzle of claim 16, wherein the screen member comprises a plurality of holes selected from slots and channels.
19. The nozzle of claim 16, wherein an exterior of the housing proximate the outlet comprises a truncated surface area.
20. The nozzle of claim 16, wherein the outlet comprises a concave surface facing the reservoir.
21. The nozzle of claim 16, wherein the outlet comprises a concave surface area facing an exterior of the housing.
22. The nozzle of claim 21, further comprising:
a barrel extending from the housing and having a passageway therethrough extending to a barrel outlet, the passageway in communication with the housing outlet and through which the liquid carbon dioxide passes to phase transfer into gaseous carbon dioxide and carbon dioxide pellets in the passageway;
a plurality of apertures extending through the barrel, each one of the plurality of apertures having a first end open at the passageway and angled toward the reservoir, and a second end opposite the first end and open to an exterior of the barrel, the plurality of apertures venting at least a portion of the gaseous carbon dioxide from the passageway.
23. The nozzle of claim 22, further comprising an electrical insulator mounted to the barrel, and a voltage source connected to the barrel for actuation to mitigate electro-static charges of the carbon dioxide pellets.
24. A nozzle for providing carbon dioxide for cleaning, comprising:
a reservoir for receiving liquid carbon dioxide;
a barrel defining a passageway therethrough, the passageway extending to an outlet of the barrel, the barrel being free from overlap with the reservoir along a longitudinal axis of the barrel;
an orifice effecting fluid communication between the reservoir and the passageway, and through which the liquid carbon dioxide flows to phase transfer into gaseous carbon dioxide and carbon dioxide pellets in the passageway; and
a screen member constructed and arranged for interrupting flow of the carbon dioxide pellets greater than a select size from being emitted from the passageway of the barrel; and
the barrel further comprises a plurality of apertures extending therethrough a wall of the barrel.