VUTRAX Application: Radio Frequency

PCB Design Software for Radio Telemetry Applications

There are many ECAD solutions to handle digital design adequately, but very few offer analogue capability ...and none can match VUTRAX in RF applications. Physical placement considerations also require design software with mechanical capabilities ...another area where VUTRAX offers unique benefits.

PCB design software which includes a mechanical CAD capability, brings extra benefits to companies that design PCBs and compatible housings. Wood and Douglas Limited (a leader in radio telemetry) is such a company. It offers UK designed and built equipment for virtually every application, in areas of rising demand for the portability which wireless links offer.

Remote control of mechanical equipment can mean greater safety for operators; CCTV surveillance offers increased security; and remote monitoring of unmanned sites for gas, water and electricity utilities is increasing. Radio can provide the link for the data, pictures and control functions in all these applications, without the costs of cabling.

Monitoring equipment has become more complex. It can watch more functions and report intelligently, dialling up specified telephone numbers and triggering pre-recorded messages, while scanning telemetry enables a base station to interrogate multiple outstations autornatically. Telemetry signals (which are relatively low power) have to face the hostile, large signal environment of today's VHF and UHF bands. By designing products that routinely exceed the minirnum requirements laid down in the Government Approval Specifications, Wood & Douglas can provide robust solutions to such demanding conditions and environments. Ranges of 10-15km can be achieved as a result.

Being able to design both PCBs and housings using the same software and commands has great benefits for designers. It cuts design time and ensures better compatibility between PCB and housing.

The Technical Drawing Module of VUTRAX offers powerful 2D facilities, although it does not claim to replace specialised mechanical CAD programmes. It enables the generation of drawings and diagrams, while mechanical parts can be stored in a library for future use. Drawings can be scaled or exploded and library parts can assume any scale or rotation. 31 user-definable script fonts are available for text and graphics on drawings or to illustrate handbooks.

A large design department at Wood and Douglas continually works on developing new products which have to meet exacting international standards. Some countries in the world are now adopting the more liberal approach of the UK Authorities, in allowing licence-free operation when using approved radio hardware in the low-power radio frequency allocations. This has led to a proliferation of applications for radio in all manner of industries,

Design problems are not simple. When committed to a PCB layout, theoretically-correct RF circuitry can often fail to perform to expectations, due to the manner in which the board has been laid out. Physical placement and arrangement of components and tracking can be critical. A poor layout will yield a high-frequency circuit at best inoperable and at worst, convert it into a source of unstable oscillation that will interfere with adjacent circuits and products. This work is made easier if a fast re-design tool is available: this is where VUTRAX scores, because changes made at one level are transferred through all layers of the software automatically.