Newsletter 2017.3

Antenna Magus Version 2017.3 released!

Version 2017.3 sees a number of small new features and improvements as well as a number of new antennas. This newsletter will the new antennas and some of the features and extensions that have been made available. For more comprehensive information please read the full release notes.

New Antennas

The new antennas (which brings the total number of devices in Antenna Magus to 324) are:

  • Planar WBAN dual-band button antenna
  • UWB WBAN Multislot Antenna with Screening Backplane
  • Folded Spherical Helix Monopole with Cone

Wireless Body Area Network (WBAN) antennas

Wireless body area networks - also known as body sensor networks (BSNs) - can be defined as systems that provide wireless communication between wearable or implantable electronic devices. The network may also include other forms of wearable technology, as well as devices carried on various body positions (e.g. pockets, bags and in-hand). If a WBAN network includes a so-called ‘gateway’ device - connecting wearable devices to the internet – it is termed a wireless personal area network (WPAN). Such networks may provide inexpensive and real-time monitoring services – particularly useful in applications where certain information must trigger an immediate response (e.g. monitoring for medical emergencies)

UWB WBAN Multislot Antenna with Screening Backplane
Image of the UWB WBAN Multislot Antenna with Screening Backplane.

In recent years, ultra-wideband (UWB) technology has received great interest for wireless body area networks. A challenge for the design of WBAN antennas remains their potential sensitivity to the proximity of the human subject.

The Multislot Antenna with Screening Backplane (MSA-BP) structure was designed using a desensitization technique, in order to reduce the effect of the human body on the overall performance (see this antenna’s Information Document in Antenna Magus for literature references). The design provides a wideband impedance match with a reflective metallic backplane to reduce backward radiation.

Typical gain: 0.75f0, f0 and 1.25f0
Typical reflection coefficient versus frequency
WBAN Dual-Band Button Antenna
Image of the WBAN Dual-Band Button Antenna.

This dual-band antenna is specifically developed for WPAN applications. The antenna has a different radiation pattern shape in each of the performance bands. This allows different modes of operation

The new antennas (which brings the total number of devices in Antenna Magus to 324) are:

  • In the lower 2.4 GHz band the antenna radiates with a quasi-monopole shaped radiation pattern. This is ideal for on-body communication with other wearable devices.
  • In the higher 5 GHz band, the antenna radiates a more directed broadside radiation pattern (similar to a PIFA). This pattern is well suited to off-body communications.

The antenna is extremely compact and could be incorporated into clothing items using different manufacturing techniques. While this design is specifically focused on using the 2.4GHz and 5GHz WLAN bands, optimisation techniques can be used in the export models to achieve dual band performance at other frequencies.

Total gain: 2.45 GHz, 5.2 GHz and 5.8 GHz
Typical reflection coefficient versus frequency
Folded Spherical Helix Monopole with Cone (FSHM with Cone)
Image of the Folded Spherical Helix Monopole with Cone (FSHM with Cone).

Antenna Magus includes a large selection of antennas that can be used as base-stations in a WPAN system or integrated in devices that will form part of a WBAN network. In the latter case particularly, the most compact antenna possible is often desirable.

The Folded Spherical Helix Monopole with cone (FSHM with cone) is related to the FSHM, which is already included in Antenna Magus. It sees the addition of a monocone at the centre of the spherical helix structure and instead of feeding the antenna at one of the helix legs – as is the case with the FSHM - the antenna is fed at the bottom of the monocone. These changes transform the original FSHM - which is a narrowband self-resonant structure - into an ultra-wideband antenna with an impedance bandwidth > 6:1. Though larger than the narrowband FSHM, the FSHM with cone remains a compact and stable structure.

For a 7-arm FSHM with cone the input impedance is close to 50 Ω, but this can be adjusted by varying the number of helical arms and the number of turns. At the lower end of the band the radiation pattern is similar in form to that of a standard dipole antenna. At higher frequencies the maximum gain increases and the isometric-in-a-plane radiation pattern starts squinting upward away from the ground plane.

VSWR comparison between different monopole topologies
Total gain: fmin, 3fmin and 8fmin

New Features and Extensions

Offset Reflector Objectives

The design objectives of all offset reflector antennas have been extended to allow the design for either F/D (focal distance to parent reflector diameter) or F/Dp (focal distance to projected reflector diameter). Irrespective of which value is specified both ratio values will be shown as a derived value.

Compare Window

Antenna Magus has introduced the Compare Window which allows the user to compare designs of different devices in the Collection. The first version only allows the comparison of physical size and 2D performance data for designs of different devices, however, these capabilities will be expanded in future versions to allow the comparison of design related values (Objectives, Parameters), 3D Far field patterns and achieved performance against a Specification.

Compare Window Button on Ribbon

Colour Picker

It is now possible to change the colour of a design by simply clicking on the existing colour indicator next to a design. If the colour is changed in Design Mode, the change will also be reflected in the Compare Window, should that particular design form part of a Compare Set, and vice versa.

Colour picker