Helical antenna and in-vehicle antenna including the helical antenna
US8242964B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jan 7, 2010 |
| Grant date | Aug 14, 2012 |
| Priority date | — |
| Expiry date | Nov 21, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q3/30
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A helical antenna includes a ground plate, a first helical portion spirally wound perpendicular to the plate, a second helical portion spirally wound perpendicular to the plate and surrounding the first helical portion radially outward of the first helical portion, and a feeder circuit. The circuit includes an oscillator, a divider connected to the oscillator, a first phase shifter connected between a first output terminal of the divider and a feeding point of the first helical portion, and a second phase shifter connected between a second output terminal of the divider and a feeding point of the second helical portion. Length of one turn of the first helical portion is equal to a result of multiplication of a wavelength of oscillation of the oscillator by N. Length of one turn of the second helical portion is equal to a result of multiplication of the wavelength by M (M>N).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.