Pewter of the Bronze Age in the Near East. The earliest piece of pewter found is from an Egyptian tomb from 1450 BC. The constituents of pewter were first controlled in the 12th century by town guilds in France. By the 15th century, the Worshipful Company of Pewterers controlled pewter constituents in England. This company originally had two grades of pewter, but in the 16th century a third grade was added. The first type, known as "fine metal", was used for tableware. It consisted of tin with as much copper as it could absorb, which is about 1%. The second type,
Distributed element filter with the microwave band (wavelength less than one metre). Distributed element filters are used in many of the same applications as lumped element filters, such as selectivity of radio channel, bandlimiting of noise and multiplexing of many signals into one channel. Distributed element filters may be constructed to have any of the bandforms possible with lumped elements (low-pass, band-pass, etc.) with the exception of high-pass, which is usually only approximated. All filter classes used in lumped element designs (Butterworth, Chebyshev, etc.) can be implemented using a distributed element approach. There are many component forms used to construct distributed element filters,