



Radio Frequency Bridges 
Bridge
networks, DC to RF: Principles and overview . + downloadable references, manuals, etc. Part 1: WheatstoneChristie Bridge. Generalising the bridge. Voltagesplitting networks. Part 2: Part 3: Practical impedance bridges. Admittance bridge. The universal bridge. Vector and scalar addition. Impedance magnitude bridge. Monitoring Bridges. 

6.2 Current transformers for RF bridges and ammeters Part 1: Intro. Equivalent circuit. Models. Transfer function. Output impedance. Insertion impedance. Part 2: LF response. Core selection. Propagation delay. Secondary capacitance. 

Part 3: Multiple secondaries. 6.3 Transmission bridges. Part 1: Current transformer bridges: Low frequency compensation. DoumaBuschbeck (capacitive voltage sampling) bridge. 6.4 Reflectometry. Part 1: <writing in progress>. 6.5 MagnitudeDifference Bridges. Part 1: Intro. Prototype currenttransformer magnitudebridge. Insertion defect. Loadside voltage sampling. Port balancing. RVS. CVS. Detectors and summing networks. Absolute measurements. Part 2: The bridge as an analog computer. Resistance bridges. Part 3: Phasor theorems. Conductance bridges. <writing in progress>. The G3GFC M50 Match Meter: Details of the original prototype units. Impedance and admittance measurement using scalar voltage samples. + spreadsheet YZ_scalar_sim.ods (8 worksheets, + macros. 1 MiB). Transmission bridge and Zmatching patents. 
Background theory and experiment 
Evaluation
and optimisation of currenttransformer bridges . The Faraday shield, throughline mismatch; compensation for parasitic inductance; propagation delay and phase neutralisation. A selfevaluating precision reference bridge. A 50 Ω transmission bridge with phase accuracy better than ±0.1° and magnitude accuracy better than ±0.2% over the 1.6 MHz to 30MHz range. 

Current transformer efficiency factor
. + spreadsheet Itr_effy.ods (v 1.01). Analysis of Herzog's currenttransformer LFcompensation method. + spreadsheet Herzog_LF.ods . + Herzog's patent US 4739515 (1988). The maximallyflat current transformer . + spreadsheet maxflat_sim.ods . Amplitude response of conventional and maximallyflat current transformers. + spreadsheets Maxflat_test1.ods & Maxflat_test2.ods . The maximallyflat transmission bridge . + spreadsheets maxflat_prelim.ods , maxflat_mtpri.ods & maxflat_brgd.ods . + LT SPICE files maxflat_v_i.asc & maxflat_brg.asc . LTspice  free SPICE simulator from Linear Technology. Analysis of Douma's generator powerfactor correction scheme. + Douma's patents US 2734169 (1956) & US 2808566 (1957). 



