Single-branch filters are still popular and are commonly used for power quality improvement purposes. Analysis of a single-branch filter is a relatively simple task. Although individual filters tuned to specific harmonics can be easily designed, after connecting them into a group it turns out that the capacitance and inductance mutually influence each other, distorting the resulting frequency characteristics. This article presents a matrix method for design a group of single-branch filters, so that the resultant frequency characteristic satisfies the design requirements including the requirements for location of the frequency characteristic maxima. Designer indicates the frequencies of the parallel resonances
 Pasko M., Lange A. Influence of arc and induction furnaces on the electric energy quality and possibilities of its improvement. Electrical Review 06: 67-74 (2009).
 Badrzadeh B., Smith K.S., Wilson R.C., Designing Passive Harmonic Filters for Aluminum Smelting Plant. IEEE Transactions on Industry Applications 47(2) (2011).
 Gerçek C.Ö., Ermis M., Ertas A., Köse K.N., Ünsar Ö., Design, Implementation, and Operation of a New C-Type 2nd Harmonic Filter for Electric Arc and Ladle Furnaces. IEEE Transactions on Industry Applications. 47(4): 1545-1557 (2011).
 Lange A., Pasko M., Selected problems of power energy quality in coal mines and steelworks. Electrical Review 6: 150-153 (2012).
 Lange A., Pasko M., Reactive power compensation and filtration of higher harmonics generated to the network by arc furnaces. Electrical Review 10a: 15-18 (2012).
 Dugan R., McGranaghan M., Electrical power systems quality. McGraw-Hill (2002).
 Hanzelka Z., Series and parallel resonance, Handbook of power quality. red. Angelo Baggini. John Wiley & Sons Ltd (2008).
 Klempka R., Hanzelka Z., Varetsky Y., Bank Harmonic Filters Operation in Power Supply System - Cases Studies. Power Quality Issues, Ahmed Zobaa (ed.), InTech, DOI: 10.5772/53425, (2013).
 Nassif A.B., Xu W., Freitas W., An Investigation on the Selection of Filter Topologies for Passive Filter Applications. IEEE Transactions On Power Delivery 24(3) (2009).
 Pasko M., Lange A., Compensation of the reactive power and filtration of high harmonics by means of passive LC filters. Electrical Review 4: 126-129 (2010).
 Klempka R., Double tuned filters designed by using genetic algorithm. JUEE Electrical Power Quality and Utilisation, Kraków, 9(2): 39-62 (2003) (in polish).
 Klempka R., A New Method for the C-Type Passive Filter Design. Electrical Review 7a, pp. 277-281 (2012).
 Klempka R., Designing a group of single-branch filters, Electrical Power Quality and Utilisation. EPQU’03, 17-19 September, Kraków (2003).
 Klempka R., Passive Power Filter Design Using Genetic Algorithm. Electrical Review 05: 294-301 (2013).