1. An antenna comprising:
a ground conductor; and
an antenna element portion for sending and receiving electromagnetic wave signals, the antenna element portion comprising:
a coaxial cable including a center conductor and an outer conductor;
a feeding point connected to a feeding system and disposed between the ground conductor and a first end of one of the center conductor and the outer conductor;
a short-circuit portion that electrically connects the ground conductor and a first end of the other one of the center conductor and the outer conductor; and
a conductor connection portion that electrically connects a second end of the center conductor and a second end of the outer conductor, wherein:
an overall length of the coaxial cable is equal to or less than \xbd of a wavelength corresponding to the minimum series resonance frequency; and
a distance between the center conductor and the outer conductor is equal to or less than 1100 of a wavelength corresponding to the minimum frequency of antenna operation.
2. The antenna according to claim 1, wherein:
the antenna element portion comprises at least two antenna element portions;
the at least two antenna element portions have the feeding point in common; and
the at least two antenna element portions have the coaxial cables each of which has different dimensions from each other.
3. The antenna according to claim 1, further comprising: a conductor to be used as a second antenna element portion, the conductor being connected in parallel to the feeding point.
4. The antenna according to claim 1, wherein:
the feeding point is fed with power by use of a feeding coaxial cable; and
the coaxial cable of the antenna element portion and the feeding coaxial cable are formed with a single coaxial cable.
5. The antenna according to claim 1, wherein the short-circuit portion comprises a conductive foil including an adhesive coating.
6. A wireless device that communicates information through electromagnetic wave signals, the wireless device being provided with an antenna comprising:
a ground conductor; and
an antenna element portion for sending and receiving the electromagnetic wave signals, the antenna element portion comprising:
a coaxial cable including a center conductor and an outer conductor;
a feeding point connected to a feeding system and disposed between the ground conductor and a first end of one of the center conductor and the outer conductor;
a short-circuit portion that electrically connects the ground conductor and a first end of the other one of the center conductor and the outer conductor; and
a conductor connection portion that electrically connects a second end of the center conductor and a second end of the outer conductor, wherein:
an overall length of the coaxial cable is equal to or less than \xbd of a wavelength corresponding to the minimum series resonance frequency; and
a distance between the center conductor and the outer conductor is equal to or less than 1100 of a wavelength corresponding to the minimum frequency of antenna operation.
7. The wireless device according to claim 6, wherein:
the antenna element portion comprises at least two antenna element portions;
the at least two antenna element portions have the feeding point in common; and
the at least two antenna element portions have the coaxial cables each of which has different dimensions from each other.
8. The wireless device according to claim 6, further comprising: a conductor to be used as a second antenna element portion, the conductor being connected in parallel to the feeding point.
9. The wireless device according to claim 6, wherein:
the feeding point is fed with power by use of a feeding coaxial cable; and
the coaxial cable of the antenna element portion and the feeding coaxial cable are formed with a single coaxial cable.
10. The wireless device according to claim 6, wherein the short-circuit portion comprises a conductive foil including an adhesive coating.
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. An electrical component comprising a substrate adapted for surface mounting and connection to a host printed circuit board forming a bus interface circuit, the component including a common-mode rejection filter mounted to the substrate and at least one circuit protection element, the substrate including a plurality of connection electrodes including filter electrodes connected to the filter and protection electrodes connected to the protection element, the electrodes for enabling direct mechanical and electrical connection of the component to the host printed circuit board.
2. The electrical component set forth in claim 1 wherein the protection element is an overcurrent protection element.
3. The electrical component set forth in claim 2 wherein the overcurrent protection element comprises a polymeric positive temperature coefficient (PPTC) resistor element.
4. The electrical component set forth in claim 1 wherein the substrate comprises a PPTC material layer forming the PPTC resistor element and wherein filter electrodes are electrically insulated from the PPTC material layer.
5. The electrical component set forth in claim 1 wherein the common-mode rejection filter comprises a multi-winding broadband transformer including a ferrite core and wherein the windings are connected between separate ones of the filter electrodes.
6. The electrical component set forth in claim 5 wherein the multi-winding broadband transformer comprises a ferrite core having two apertures and wherein at least a pair of windings pass through each aperture.
7. The electrical component set forth in claim 1 wherein the protection element is an overvoltage protection element.
8. The electrical component set forth in claim 7 wherein the substrate includes a ground electrode and the overvoltage protection element is connected between a filter electrode and the ground electrode.
9. The electrical component set forth in claim 1 wherein the protection element comprises an overcurrent protection element and an overvoltage protection element.
10. The electrical component set forth in claim 9 wherein the overcurrent protection element comprises a PPTC resistor between overcurrent protection connection electrodes and wherein the overvoltage protection element is connected between a filter electrode and a ground electrode of the substrate.
11. The electrical component set forth in claim 10 wherein the wherein the overvoltage protection element is connected between the overcurrent electrode and a ground electrode of the substrate.
12. An electrical device comprising:
a flat substrate having a top major surface and a bottom major surface substantially coplanar therewith, the bottom major surface adapted to be surface-mounted to a host printed circuit board,
first, second, third, fourth, fifth and sixth spaced-apart surface mount contact sets wherein a contact set includes a contact pad formed on the top major surface and an interconnected contact pad formed on the bottom major surface,
an overcurrent protection element connected between first and second contact sets, and
a multi-winding common-mode rejection filter element located at the top major surface and having a first winding connected between the third and fourth contact sets and a second winding connected between the fifth and sixth contact sets.
13. The electrical device set forth in claim 12 wherein the overcurrent protection element comprises a polymeric positive temperature coefficient (PPTC) resistor element, wherein the substrate comprises a layer of PPTC material forming the PPTC resistor element, and wherein the third, fourth, fifth and sixth contact sets are electrically insulated from the layer of PPTC material.
14. The electrical device set forth in claim 12 wherein the common-mode rejection filter element comprises a multi-winding broadband transformer including a ferrite core and wherein windings are connected respectively to top surface connection pads of the third, fourth, fifth and sixth contact sets.
15. The electrical device set forth in claim 14 wherein the device includes seventh, eighth, ninth and tenth contact sets, wherein the common-mode rejection filter element includes a second multi-winding broadband transformer including a ferrite core and windings connected respectively to top surface connection pads of the seventh, eighth, ninth and tenth contact sets.
16. The electrical device set forth in claim 14 wherein the multi-winding broadband transformer comprises a ferrite core having two apertures and wherein a first pair of windings pass through a first aperture and connect respectively to the third and fourth contact sets, wherein the substrate defines seventh, eighth, ninth and tenth contact sets and wherein a second pair of windings pass through a second aperture and connect respectively to the seventh, eighth, ninth and tenth contact sets.
17. The electrical device set forth in claim 14 wherein the substrate defines a ground contact set and further comprising a first overvoltage protection element connected between one of the third and fourth contact sets and the ground contact set, and further comprising a second overvoltage protection element connected between the fifth and sixth contact sets and the ground contact set.
18. An electrical component for a circuit supporting a powered data interface comprising:
(1) a flat substrate having:
(a) a top major surface and a bottom major surface substantially coplanar therewith,
(b) a pattern of electrically conductive top traces defined on the top major surface,
(c) a pattern of electrically conductive bottom traces defined on the bottom major surface for electrically connecting the component to a host printed circuit board providing the powered data interface,
(d) vias passing through the substrate for interconnecting separate ones of the top traces to separate ones of the bottom traces to form overcurrent protection electrodes and filter electrodes,
(e) a layer of polymeric positive temperature coefficient (PPTC) resistor material forming an overcurrent protection element for protecting a power supply to the data interface bus against overcurrent and connected to the overcurrent protection electrodes, and
(f) insulating material for isolating the filter electrodes from the overcurrent protection element, and
(2) a common-mode noise rejection filter element located at the top major surface and connected to the filter electrodes for protecting data lines of the powered data interface against common-mode interference.
19. The electrical component set forth in claim 18 wherein the common-mode noise rejection filter element comprises at least one broadband transformer having windings connected to the filter electrodes.
20. The electrical component set forth in claim 18 further comprising at least one ground electrode isolated from the overcurrent protection element and at least one overvoltage protection element connected between a filter electrode and the ground electrode.
21. The electrical component set forth in claim 20 wherein an overvoltage protection element is connected between each filter electrode and a ground electrode of the component.
22. The electrical component set forth in claim 18 wherein the pattern of electrically conductive bottom traces is arranged to enable surface mounting of the electrical component to the host printed circuit board.