ANTENNA END FILTER ARRANGEMENT

• US 20090058556A1
• Filed: 11/07/2005
• Published: 03/05/2009
• Est. Priority Date: 12/02/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Powerwave Comtek OY (Powerwave Technologies Incorporated)
• Inventors: Niiranen, Erkki, Ala-Kojola, Jouni
• Granted Patent: US 8,125,296 B2
• Time in Patent Office: Days
• US Class Current: 333/132
• CPC Class Codes: H01P 1/2053 the coaxial cavity resonators being disposed parall to each other
• CPC Class Codes: H04B 1/44 Transmit/receive switching
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion

Abstract

An arrangement for filtering the transmitting signals in a radio device using frequency division duplex. In a radio transmitter, in which the transmitting signal is divided to a plurality of antennas (ANT1, ANT2, ANT3) radiating to different sectors, the filtering required in transmitting is mostly carried out by a shared transmitting filter (240) before the transmitting signal is divided. The rest of the filtering is carried out separately on each partial transmitting signal (T₁; T₂; T₃) in the reduced transmitting side (TXF1; TXF2; TXF3) of the duplex filter. The filters and the divider (250) preferably form an integrated filter unit, in which they are connected to each other by simple coupling elements. The space required by the filters of the antenna end of the radio device is significantly reduced, and the material and assembly costs of the antenna end in production are reduced.

Claims

1. A filter arrangement at an antenna end of a radio device using frequency division duplex, the antenna end having a divider (250) for dividing a radio transmitting signal (T_k) coming from a power amplifier to antennas (ANT1, ANT2, ANT3) radiating in different sectors, which arrangement comprises a separate transmitting filter (TXF1;

TXF2;

TXF3) for each antenna, output of which filter being coupled to the antenna in question and one output of the divider being coupled to the input of the transmitting filter, characterized in that it comprises a shared transmitting filter (240) for the antennas and the output of the shared transmitting filter is coupled to the input of the divider (250), for simplifying separate transmitting filters and for reducing the space required by the antenna end of the radio device.

2. An arrangement according to claim 1, characterized in that the shared transmitting filter (240) comprises a bandpass part (241) and a low-pass part (242) connected in series.

3. An arrangement according to claim 2, characterized in that the bandpass part (241) of the shared transmitting filter and the separate transmitting filters (TXF1, TXF2, TXF3) consist of coaxial resonators.

4. An arrangement according to claim 3, characterized in that a filter unit (200), which comprises a shared transmitting filter (240), the divider (250) and the separate transmitting filters (TXF1, TXF2, TXF3), forms a unitary, conductive housing, the inner space of which is divided by conductive partition walls into cavities, each of said coaxial resonators comprising an inner conductor in a single cavity and conductor walls confining the cavity.

5. An arrangement according to claim 4, characterized in that the low-pass part (242) of the shared transmitting filter is located in one cavity.

6. An arrangement according to claim 4, characterized in that the divider (250) is located in one cavity.

7. An arrangement according to claim 6, wherein the divider (250) is a Wilkinson divider comprising an input line and division lines, characterized in that a division conductor of each division line is a strip conductor and it extends to the cavity of first resonator (R11;

R21;

R31) of one separate transmitting filter to couple the divider to the filter in question.

8. An arrangement according to claim 3, characterized in that the divider is connected to separate transmitting filters by coaxial cables.

9. An arrangement according to claim 3, characterized in that the number of resonators in each separate transmitting filter is not more than four.

10. An arrangement according to claim 9, characterized in that the number of resonators in each separate transmitting filter (TXF1;

TXF2;

TXF3) is three, and the number of resonators in the bandpass part (241) of the shared transmitting filter is five.

11. An arrangement according to claim 1, characterized in that the number of antennas and separate transmitting filters is three.