TFS400

      The TFS400 is designed as VI telefilter which is suitable for GSM, DCS 1800 and dual band receivers. It can especially be used in the first IF in which full channel selectivity is not necessary. Due to the high frequency the filter is small, thus it saves cost and space on the printed circuit board. As it has symmetrical input and output it does not need any transformation networks in state of the art IC transceiver concepts in which symmetrical inputs and outputs are favourable.
      Some specifications TFS400  have been concluded into several points as follow. The first one is about its insertion loss which would be typ 4.5dB and max 6.5dB. The next one is about its centre frequency which would be typ 400.000MHz. The next one is about its usable signal bandwidth which would be min 140KHz. The next one is about its 3dB bandwidth which would be typ 360kHz and min 280kHz. The next one is about its relative attenuation which would be typ 25dB and min 15dB for 400MHz ± 400 kHz and would be typ 35dB and min 27dB for 400 MHz ± 600 kHz and would be typ 66dB and min 35dB for 400 MHz ± >1 MHz. The next one is about its group delay ripple 400 MHz ± 70 kHz which would be typ 0.5 s and max 2 s. The next one is about its operating temperature range which would be from -20°C to +70 °C. The next one is about its temperature coefficient of frequency which would be ca. -0.036 ppm/K2. The next one is about its frequency inversion temperature which would be + 20 °C.
      TFS400  should be noted that reference level for the relative attenuation arel of the TFS 400_1 is the minimum of the pass band attenuation amin. The minimum of the pass band attenuation amin is defined as the insertion loss ae. The centre frequency fo is the arithmetic mean value of the upper and lower frequencies at the 3 dB filter attenuation level relative to the insertion loss ae. The nominal frequency fN is fixed on 400,000 MHz without tolerance. The given values for the relative attenuation arel and for the group delay ripple have to be reached at the frequencies given below also if the centre frequency fo is shifted due to the temperature coefficient of frequency TCf in the operating temperature range and due to a production tolerance for the centre frequency fo. And so on. For more information please contact us.