DE102005043373A1 - Electrical module with duplexer circuit, has antenna terminal connected to transmit filter and to receive filter via series capacitor with shunt inductor between antenna connection and ground to act as LC impedance matching circuit - Google Patents

Abstract

The module comprises a transmitter-path filter (F1) connected directly to an antenna terminal to which is also connected one terminal of an inductor, the other terminal being grounded. A receiver-path filter (F2) is connected to the antenna terminal via a capacitor (C), so that the inductor and capacitor together constitute an impedance matching circuit (MA). The capacitor and inductor may be formed as conductive areas on the multilayer substrate, e.g. of LTCC, on which the module is formed, and the filters may be of SAW or BAW type. Electrical element with a duplexer circuit consists of an antenna connection (ANT), which is connected leading with a transmission path (TX) and a receiving path (RX).

Description

Duplexers are z. B. from the document US 5,864,265 known.

A to be solved The task is to provide a low-loss electrical component with a Specify duplexer.

It For example, a device is specified with a duplexer that has an antenna path which branches into a transmission path and a reception path. The duplexer comprises a transmission filter arranged in the transmission path, a reception filter arranged in the reception path and a reception filter upstream matching circuit, which is arranged in the receiving path series capacitance and having a shunt arm against ground, in which an inductance is arranged is. The component further comprises a carrier substrate in which realizes the inductance is.

One Matching network comprising a parallel inductance and a Series capacitance, is one with respect to integration in a carrier substrate Matching network with a transmission line (eg λ / 4 line) especially space saving.

The Substrate includes metallization levels, between which dielectric Layers are arranged, the z. B. LTCC ceramic included. Different metallization levels are electrically connected to each other by means of plated-through holes. The inductance is preferably in an inner Me metallization of the carrier substrate educated. As material for but the dielectric layers are also any electrical insulating materials, which ensure a relatively high quality of the inductance can.

The inductance can be folded by a spiral or meandering Track be realized. The inductance can be arranged one above the other, by means of Having a plated through-connection conductive parts.

The inductance is preferably connected directly to the antenna path. The serial capacity is in a variant in the carrier substrate realized and includes z. B. at least two superposed conductive Surfaces. The serial capacity can also as a multi-layer capacity formed with interlocking, in cross-section comb-like electrode surfaces be. The trace, which realizes the inductance, can be used for formation at least part of the series capacity.

The Transmit filter and the receive filter have in a variant acoustic surface waves and / or bulk waves operating, electrically interconnected Resonators on. The resonators can z. B. a Laddertype arrangement (Branch circuit) form. The filters are preferably bandpass filters.

The Filters can be realized in each case in a filter chip, which on the carrier substrate mounted and with this z. B. by bumps or bonding wires conductive connected is. The filters can but also be realized in a common filter chip.

The series capacitance can be formed by an electro-acoustic resonator, the preferably opposite detunes the reception band in terms of frequency is. The electroacoustic resonator is preferably in the filter chip arranged.

Of the The transmission path and the reception path are earth-symmetrical in one variant (Single-ended). At least one of these paths, in particular the reception path, can also be earth symmetric (balanced).

The specified component will now be based on schematic and not to scale Figures explained. Show it:

1 an equivalent circuit diagram of a duplexer;

2 in schematic cross-section, a component having a multilayer substrate and an inductance integrated therein.

1 shows a duplexer circuit with a transmission filter F1, a reception filter F2 and a matching network MA. The matching network MA comprises a series capacitance C and a parallel inductance L connected to the antenna. F1 and F2 are band-pass filters.

The Circuit has a transmission path TX and a reception path RX, the antenna side are conductively connected to each other. The matching network MA can be assigned to the receive path RX.

In 2 a component with a multilayer substrate SU is shown, on which a filter chip CH with the filters F1, F2 is fixed by means of bumps and to which it is conductively connected. The series capacitance may be arranged in the substrate SU or formed as a resonator which is arranged in the filter chip.

LIST OF REFERENCE NUMBERS

• ANT

  antenna connection

  C

  series capacitance

  CH

  filter chip

  F1

  transmission filter

  F2

  receive filter

  L

  inductance

  MA

  matching

  RX

  receive path

  RX-OUT

  Receive output of the duplexer

  SU

  carrier substrate

  TX

  transmission path

  TX-IN

  Send input of the duplexer

Claims (9)

Electrical component with a duplexer circuit, full - one Antenna connection (ANT), which is conductive with a transmission path (TX) and a receiving path (RX) is connected, - An arranged in the transmission path (TX) Transmit filter (F1), a receive filter arranged in the receive path (RX) (F2) and a matching circuit upstream of the reception filter (F2) (MA), which in the receiving path (RX) arranged series capacity (C) and a Transverse branch to ground, in which an inductance (L) arranged is - one carrier substrate (SU), in which the inductance (L) is realized. Component according to claim 1, wherein the inductance (L) in an inner metallization of the carrier substrate (SU) is formed is. Component according to claim 1 or 2, wherein the inductance (L) to the antenna connection (ANT) is connected. Component according to one of claims 1 to 3, wherein the series capacitance (C) in carrier substrate (SU) is realized. Component according to one of claims 1 to 4, wherein the filters (F1, F2) with surface acoustic waves having working resonators. Component according to one of claims 1 to 5, wherein the filters (F1, F2) with bulk acoustic waves ar beitende resonators. Component according to one of claims 1 to 6, wherein the filters (F1, F2) are each realized in a filter chip, which on the carrier substrate (SU) is mounted. Component according to one of claims 1 to 6, wherein the filters (F1, F2) are realized in a common filter chip, the on the carrier substrate (SU) is mounted. Component according to one of Claims 5 to 8, characterized - in which the serial capacity (C) is formed by an electroacoustic resonator, which is opposite to the Receiving band detuned in terms of frequency is - in which the electroacoustic resonator is arranged in the filter chip.