Free Design Special Learning Kit

Temwell Helical Bandpass Filter Learning 

In Tx and Rx circuit designs usually need a filter to remove unwanted frequency from a signal while preserving desired frequency. There are 4 basic types of filters, one is Bandpass Filter allows all frequencies between two frequencies to pass while rejecting all others.

The Bandpass Filter is obtained by cascading a lowpass and highpass filter. It is a second order filter since it contains two reactive elements. The order of the filter depends on the number of cascading circuits using in the circuit. It will optimize the sensitivity of the Tx and Rx devices.

At VHF and UHF frequencies, the size of the coaxial cavity filter is too large for many applications. To reduce the length of the resonator, the centre quarter wave resonator is wound as a Helical. It is based on one-quarter wavelength long technology, but preserving high Q value and low insertion loss in smaller size.

TEMWELL dedicate to designing and manufacturing RF Filter over 25 years. Besides large scale production commercial industries, we also support small quantity but frequencies in diversity users, such as RF equipment testing centers, laboratories, amateur radio, RF circuit design freelance, academic research unit, students etc.

 
**You can easy learn the following through Temwell Helical Bandpass Filter learning kit.
** Network analyzer using and measurement (e.g. calibration)
**RF filters waveform specs S11, S22 (e.g. center frequency, bandwidth, attenuation, second harmonic)
** How the RF filters waveform changes by tuning screws on the filters (e.g. frequency shift)

Our Helical Bandpass Filter supports from 45 MHz to 2.6 GHz, the learning kit including the most widely used are 7H series each filter is 12.5 mm height and 7.6 mm wide, and 5W series each filter is 8.6 mm height and 5.6 mm wide. Both series including 50 ohm and 75 ohm, power sustain up to 5 watts. The optional frequencies sort by applications: Two-Way Radio, Ham Radio, Broadband and NB-IoT. Frequencies for instance: 60 MHz, 70 MHz, 80 MHz, 90 MHz, 128 MHz, 140 MHz, 146 MHz, 157 MHz, 160 MHz, 172 MHz, 180 MHz, 223.5 MHz, 375 MHz, 380 MHz, 418 MHz, 435 MHz, 450 MHz, 455 MHz, 460 MHz, 474 MHz, 480 MHz, 500 MHz, 530 MHz, 575 MHz, 625MHz, 650 MHz, 666 MHz, 725 MHz, 700 MHz, 808 MHz, 850 MHz, 868 MHz, 883 MHz, 881.5 MHz, 900 MHz, 902.5 MHz, 915 MHz, 925 MHz, 947.5 MHz, 950 MHz, 1270 MHz, 1282.5 MHz, 1489 MHz, 1575 MHz, 1950 MHz, 2400 MHz, 2450 MHz etc.

Additionally, we developed helical filter alternatives for Toko standard series as following for learning kit option.

**Toko 7HW and 7HT v.s. Temwell 7H series
**Toko 5HW and 5HT v.s. Temwell 5R series (same size as 5W series but vertical ground pin)

All are Pin to Pin (same footprint) as Toko, and performance better and compatible.

Temwell filter learning kit helps you get tunable Helical Bandpass Filters without design fee, in the shortest 5-7 working days delivery and quality reliable (RoHS, REACH, ISO certificated). All made in Taiwan, you can quickly scan the following a standard price list.

For more technical information (how to make calibration, how to tuning etc) and test reports:

** /en/page-categories/technical-information
** https://temwell.shoplineapp.com/pages/filter-school

 
Finally, if you need not just filters but also PCB assembly components. Please feel free to contact us whenever wherever, if you have more questions about our products and service. TEMWELL will be always right here to be your good RF & Microwave passive components supporter, from product design and after-sales technical consulting, to solve signals interference in RF circuits.

Double Tuning RF BandPass Helical Filter 7H2/ 7S2/ 5W2/ 5R2 Series 50Ω /75Ω Each Filter is Tunable  > ±5MHz

Product Specification: Series : Temwell 7H2 / 7S2/ 5R2/ 5W2 Series Tuning pole : Double Tuning Centre Freq. (Fo) : 42~1300 MHz Bandwidth (B.W.):  2~100MHz Case (H x L x W) :   12.5 x 7.6 x 15.3 mm (7H2)/ 15.2 x 7.6 x 8.6 mm (7S2)   11.2 x 5.6 x 8.6 mm (5W2)/ 11.2 x 5.6 x 8.6 mm (5R2) Catalog Part 1: Impedance 50Ω   Catalog Part 2: Impedance 75Ω

Triple Tuning RF BandPass Helical Filter 7H3/ 7S3/ 5W3/ 5R3 Series 50Ω /75Ω Each Filter is Tunable  > ±5MHz Product Specification: Series : Temwell 7H2 / 7S2/ 5R2/ 5W2 Series Tuning pole : Double Tuning Centre Freq. (Fo) : 42~1300 MHz Bandwidth (B.W.):  2~100MHz Case (H x L x W) :     12.5 x 7.6 x 15.3 mm (7H2)/ 15.2 x 7.6 x 8.6 mm (7S2)     11.2 x 5.6 x 8.6 mm (5W2)/ 11.2 x 5.6 x 8.6 mm (5R2) Catalog Part 1:  Impedance 50Ω  Catalog Part 2 :  Impedance 75Ω

Quadruple Tuning RF BandPass Helical Filter 7H4/ 5W4 Series 50Ω/75Ω Each Filter is Tunable  > ±5MHz Product Specification: Series : Temwell 7H4 / 5W4 Series Tuning pole : Quadruple Tuning Centre Freq. (Fo) : 42~2600 MHz Bandwidth (B.W.):  2~180MHz Case (H x L x W) :               12.5 x 7.6 x 30.8 mm (7H4) /              22.4 x 5.6 x 8.6 mm  (5W4) Catalog Part 1:  Impedance 50Ω Catalog Part 2 :  Impedance 75Ω