Power Splitter

Stacking with Power Splitters

Square Power SplitterThe basis of the power splitters/combiners is a construction of a square tube for the outer conductor and a round tube for the inner conductor. It forms a quarterwave coaxial impedance transformer. The relation D/d influences the resistance/impedance of the splitter. As with the stacking by coax-cables the impedance transformation will be made with lengths of λ/4. A halvewave-splitter consists of two quarterwave-splitters in parallel. Very good tool to construct power splitters is the program “AppCad” .The program is freeware, download it at. www.hp.woodshot.com

Splitter Zo Schema E = Z02/ ZA
Z = Z0 (see AppCad)

Splitter Quarterwave Splitter Halvewave
Type 1a: A quarterwave power splitter (2-way) Type 2a: A halfwave power splitter (2-way)
Type 1b: A 4-way splitter, right are 4 connectors Type 2b: A 4-way splitter, each side have 2 connectors

Attributes of the Power Splitters.

Type Ways Length ZE ZA Z0
1a 2x λ/4 25Ω 50Ω 35,4Ω
1b 4x λ/4 12,5Ω 50Ω 25Ω
2a 2x λ/2 50Ω 100Ω 70,7Ω
2b 4x λ/2 25Ω 100Ω 50Ω

Lengths of the inner Tubes (d) for the Bands 2m, 70cm and 23cm.

Amateurband Principle Length inner tube
2m λ/4 520mm
70cm λ/4 166mm
(RFHamdesign)
70cm λ/4 173mm
23cm 3λ/4 189mm

λ/4 Splitter, 2-way, Type 1a, needed Z=35,4Ω RFHamdesign Copper.

Type Square Inner (D) Round Tube (d) Z
1a 25x1mm 23mm 14mm 35,4Ω

λ/4 Splitter, 2-way, Type 1a, needed Z=35,4Ω.

Type Square Inner (D) Round Tube (d) Z
1a 29,5×2,8mm 24,7mm 15mm 34,4Ω
1a 23,5×1,5mm 20,5mm 12mm 36,6Ω
1a 19,5×1,5mm 16,5mm 10mm 34,6Ω
1a 30x2mm 26mm 15mm 37,5Ω

Table 2: λ/4 Splitter, 4-way, Type 1b, needed Z=25,0Ω.

Type Square Inner (D) Round Tube (d) Z
1b 25x2mm 21mm 15mm 24,7Ω
1b 19,5×1,5mm 16,5mm 12mm 23,7Ω

Table 3: λ/2-Splitter, 2-way, Type 2a, needed Z=70,7Ω.

Type Square Inner (D) Round Tube (d) Z
2a 29,5×2,8mm 24,7mm 8mm 72,1Ω

Table 4: λ/2-Splitter, 2-way, Type 2b, needed Z=50Ω.

Type Square Inner (D) Round Tube (d) Z
2b 30x2mm 26mm 12mm 50,9Ω
2b 25x2mm 21mm 10mm 49Ω

Table 4: λ/4-Splitter, 3-way, Type 1c, needed Z=28,3Ω.

Typ Square Inner (D) Round Tube (d) Z
1c 35x2mm 31mm 10mm 30,8Ω

Power Splitter Example TopviewDetailed picture of the inside.