16.3.1. Wire antenna
An effective antenna is a
λ
/4 radiator with a suiting ground plane. The simplest realization is
a piece of wire. It’s length is depending on the used radio frequency, so for example 8.6 cm
868.0 MHz and 3.1 cm for 2.440 GHz as frequency. This radiator needs a ground plane at
its feeding point. Ideally, it is placed vertically in the middle of the ground plane. As this
is often not possible because of space requirements, a suitable compromise is to bend the
wire away from the PCB respective to the ground plane. The
λ
/4 radiator has approximately
40
Ω
input impedance, therefore matching is not required.
16.3.2. Chip antenna
There are many chip antennas from various manufacturers. The benefit of a chip antenna
is obviously the minimal space required and reasonable costs. However, this is often at the
expense of range. For the chip antennas, reference designs should be followed as closely
as possible, because only in this constellation can the stated performance be achieved.
16.3.3. PCB antenna
PCB antenna designs can be very different. The special attention can be on the miniaturiza-
tion or on the performance. The benefits of the PCB antenna are their small / not existing (if
PCB space is available) costs, however the evaluation of a PCB antenna holds more risk of
failure than the use of a finished antenna. Most PCB antenna designs are a compromise of
range and space between chip antennas and connector antennas.
Proteus-III reference manual version 1.3
© August 2020
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