Premium prices for mm-wave components – are they still justified?: Page 2 of 4

September 10, 2014 //By Andy Trusler, Luso Electronics
Traditionally waveguide components at frequencies above 26 GHz have been expected to carry a much higher price tag than the equivalent products at lower frequencies, sometimes by as much as a factor of three. Nowadays this price differential may be less justified, since technology advances have largely evened out the cost of many of the steps in both design and manufacture where the imbalance had previously been most pronounced.
Design costs

In recent years, the accuracy of electromagnetic simulation software at higher frequencies has improved dramatically, meaning that a Ka-band component in WR-28 (WG22) is scarcely more difficult to design, nor takes any longer to simulate, than a C-band part in WR-137 (WG14). If design costs are amortised over a production run then only the smaller volumes that are traditionally ordered at millimetre-wave frequencies will justify a higher cost being passed onto the customer. However, once the industry adapts to the idea that a higher frequency does not necessarily imply a higher price ticket, then volumes will increase and economies of scale should serve to equalise the design costs in the two bands.

Table 1: Table of rectangular waveguide dimensions for primary bands from C-band to Ka-band, highlighting the two bands discussed in this article.

Manufacturing costs

Table 1 gives the frequency ranges and dimensions of the main band designations for rectangular waveguide (the even-numbered ones in the European WG types), with the data for WR-137 and WR-28 highlighted in pink. Since waveguide sizes were originally defined in inches, the metric sizes have been rounded to the nearest 0.01 mm. Figure 2 gives an idea of the difference in scale between the two waveguide sizes – roughly 5:1 in each dimension.

Design category: