This is radiospurs. A UK based web site for those interested in Broadcasting hardware (FM, mobile, microwaves, microstrip, power slablines, couplers)
After many years running around the broadcast, microwave, wan/lan worlds this is what we get: a suite of web sites that give you real practical information on what you have always wanted to know about Broadcasting, RF engineering and some other related topics.
General Broadcasting (in especial Band II FM):
A novel Fully Digital Stereo Encoder using asynchronous coupling and integrated audio processor.
A RDS Encoder using RDS envelope synthesis, thus avaoiding the need for a raised cosine filter.
A SNMP engine for control of TX.
RF Filters: using the classic Butterworh, Chebychev type 1, Chebychev type 2, Bessel, Elliptic, Gaussian, Legendre design methods. Complete with power analysis for those internal currents and voltages. Usefull for power filters.
Microwave Filters: Interdigital, stepped line, parallel coupled, capacitive gap are just some of the filters design techniques deployed here.
Analysis and design of microwave substrates:
Classical Microstrip, with the inverted and suspended variants.
Stripline, slabline, Power line are less known variants.
There is a catalog of substrates from well known manufactures to be used for the design or give custom parameters for you own speciality substrates.
Analysis and design of Rf an Microwave couplers and Combiners:
RF multisection hybrids, triway hybrid combiner filter.
Classic Wilkinson combiner with multisection entry and exit lines in different transfpormation formats eg: Butterworth, geometric
Multisection parallel line couplers (Edge mode, Broadside mode) using both summing and substraction modes. Custom design of edge couplers.
Based upon the LongleyRice model both point to point link and broadcast propagation analysis are provided in almost any part of the civilised world. Choose a location, view the terrain profile, enter TX, RX properties and way go to the analysis.
Preliminary, Helper propagation analysis is provided for Freespace, Fresnel Zone, Lineof Sight, Rx Sensitivity, Friis, Eglii models.
Great Circle distancing, EIRP for the antenna.
The classical Yagi Uda using either the Rothamel tables opr a custom design. The main properties, gain, 3db BW etc are given. Both the Eplane and Hplane plots are given along with the normalisedcentre currents for each element
Waveguide Horns: Eplan, Hplane, Pyramid and Conical variants are designed and analysis with radiation patterns.
Helix antenna: Both axial (classical, Woodyard varients) and normal designs, analysis with radiation patterns.
Ad-hoc items. Coaxial line, waveguide dimension (rectangular, circular), power pads/attenuators, weather conditions
Power Capacitors, Power Inductors.