Patent EP0474490A1 successfully refreshed from Google Patents.
EP0474490A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Antenna assembly
Assignee: NCR International Inc
•
Filing: 1991-09-05
•
Granted: —
•
Expires: 2011-09-05
Abstract
Abstract An antenna assembly includes a dipole antenna (D1, D2) and a monopole antenna (C1) having substantially perpendicular polarization directions. The dipole antenna (D1, D2) is provided with a balun (E1, E2) a portion (E1) of which serves as a backplane for a microstrip transmission line (G0, G1, G2) which transmits RF signals. The microstrip transmission line includes a first portion (G0) connected to a coaxial feed cable (F), a second portion (G1) having its ends respectively connected by a first switch (A) to the monopole antenna (C1) and a second switch (B) to the balun position (E1) and a third portion (G2). When the switches (A, B) are closed to render the monopole antenna (C1) operative, the third portion (G2) serves to detune the dipole antenna (D1, D2). The assembly may be formed as a two-sided printed circuit board.
Inventors
- 👤 Erik Bert Busking
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 02:13
CPC Classifications
H; H01; H01Q; H01Q21/00; H01Q21/24; H01Q9/00; H01Q9/04; H01Q9/0407; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0802
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
57 words
An antenna assembly including first (D1, D2) and second (C1) antennas having different polarization directions, characterized by switching means (A, B) adapted to render said first antenna (D1, D2) or said second antenna (C1) selectively operative, wherein said switching means (A,B) is adapted to detune said first antenna (D1,D2) when said second antenna (C1) is rendered operative.
Claim 2
Dependent Claim
80 words
An antenna assembly according to claim 1, characterized in that said first antenna is a dipole antenna (D1,D2), and said second antenna is a monopole antenna (C1), and in that said switching means includes first and second switching devices (A,B) located adjacent first and second ends of said monopole antenna (C1), operation of said first and second switching devices (A,B) to render said monopole antenna (C1) operative being effective to operatively connect a detuning element (G2/E1) to said dipole antenna.
Claim 3
Dependent Claim
147 words
An antenna assembly according to claim 2, characterized in that said dipole antenna includes first and second dipole elements (D1,D2) and in that said assembly includes microstrip transmission line means ((G0, G1, G2)/(E1), H) adapted to supply signals to be transmitted to said first and second dipole elements (D1, D2), and balun means (E1, E2), wherein said microstrip transmission line means includes first, second and third interconnected portions (G0/E1, G1/E1, G2/E1) including first, second and third conductive strips (G0, G1, G2) separated by dielectric material (50) from a fourth conductive strip (E1) forming a part of said balun means (E1, E2), wherein signals to be transmitted are coupled to said first transmission line portion (G0/E1), said first and second switches (A,B) being located adjacent opposite ends of said second transmission line portion (G1/E1) and said third transmission line portion (G1/E1) serving to detune said dipole antenna (D1,D2).
Claim 4
Dependent Claim
53 words
An antenna assembly according to claim 3, characterized in that said assembly includes a printed circuit board (12,202) constituting said dielectric material (50), and in that said dipole elements (D1, D2), said monopole antenna (C1) and said balun means (E1, E2) are provided as electrically conductive regions on said printed circuit board (12,202).
Claim 5
Dependent Claim
30 words
An antenna assembly according to claim 4, characterized in that a passive monopole matching and radiating element (C2) is provided as a further conductive area on said printed circuit board.
Claim 6
Dependent Claim
116 words
An antenna assembly according to claim 5, characterized in that said first switching device (A) includes a first diode (226) having a first terminal connected to said second conductive strip (G1) and a second terminal connected to a parallel-connected first capacitor (230) and first resistor (228) connected to said monopole antenna (C1), in that said second switching means (B) includes a second diode (236) having a first terminal connected to said second conductive strip (G1) and a second terminal connected via a parallel-connected second capacitor (240) and second resistor (238) to said fourth conductive strip (E1), and in that said second conductive strip (G1) is connected to said third conductive strip (G2) via third capacitor (250).
Claim 7
Dependent Claim
26 words
An antenna assembly according to claim 6, characterized in that an inductor (L) is coupled between said fourth conductive strip (E1) and said monopole antenna (C1).
Claim 8
Dependent Claim
37 words
An antenna assembly according to claim 7, characterized in that a coaxial feed cable (F) has its inner conductor connected to said first conductive strip (G0) and its outer conductor connected to said fourth conductive strip (E1).
Claim 9
Independent Claim
80 words
A method of transmitting data frames in a local area network including a plurality of local area network stations, each station including transceiver means to operate on a wireless transmission channel, and first and second antennas (D1, D2; C1) having different polarization direction, characterized in that said method includes the steps of; selecting one of said first and second antennas (D1, D2; C1) to be used; and detuning the non-selected one of said first and second antennas (D1, D2; C1).
References Cited (Backward Citations)
US4379296A
Cited
US4538153A
Cited
GB2176660A
Cited
EP0184383A2
Cited
US4800393A
Cited
EP0318665A2
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.