Customized RF Components and Microwave



Reduced Jamming between Wireless Power Transmitter and Receiver by TEMWELL Bandpass Filter – 915 MHz

Wireless power transmission uses inductive technologies and is applied to various applications around in our life, for example, mobile and portable devices, audio-visual equipments, table-order-systems, robots, car-mounted devices, lighting and medical equipment etc. This technology has been commercialized for wireless charging of smart phone, tablet, mouse and keyboard, digital camera, wireless bracelet, digital TV etc.

For above application circuit designs are primarily operating in the unlicensed Industrial Scientific Medical (ISM) Band which adopted e.g. IEEE 802.11 (Wi-Fi), Bluetooth, ZigBee and RFID (NFC) wireless technologies. According to ITU Radio Regulations defined the ISM Band center frequency at 915 MHz, 433.92 MHz, 2.4 GHz and 5.8 GHz that are using in US, Europe and Asia countries.

The common method of wireless power transmission uses resonators to transmit electric power through the electromagnetic resonance between (Tx) transmitter and (Rx) receiver (magnetic resonant coupling). By matching the resonance frequency of both resonators with high Q factor, electric power can be transmitted over a long distance where magnetic coupling between Tx and Rx block is low. This way also offers flexibility in the receiver load location and the transmitter charging location.

In spite of benefits are great, there are many limitations and weak points necessitating the discussion of possible solutions. One of weak points is that in wireless transmission is extremely exposed to atmospheric noise and other signals, therefore the signal transfer from transmitter to receiver experience lots of attenuation losing and distortion.

An efficient solution without changing too much on design concept that is putting Bandpass Filter in the front-end blocks for filtering noise when signals received from transmitter throughout antenna, and signals received from external cable to connect from antenna to filter and filter to LNA. *If you need power amplifier or low noise amplifier Temwell sister brand Temstron can support please contact us 


Temwell RD team has developed high attenuation Bandpass Filter in standard ISM band centre frequency 915 MHz for reducing signal interference between wireless power transmitter and receiver. Please see the following models table, which Bandwidth includes from narrow 10 MHz to wide 120 MHz. The minimum Insertion loss less than 2 dB, high Attenuation can up to 60 dB depends on stop band you need. Return loss more than 12 dB. The linear waveform is excellent. Package offers two options, Pin and Connector (SMA or N), power sustain from 1 to 10 Watts. Small size for flexible locating in your design: Pin height 12.5mm, SMA connector height 26mm.

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Standard Catalog

A.3 Pole Filter  Spec (Freq / BW) Size (LxWxH)   Accepted Type
TT67151A-915M 915MHz / 10MHz TT (22.8x7.6x12.5) Pin Type / Module Type
915MHz / 15MHz TT (22.8x7.6x12.5) Pin Type / Module Type
TT67840B-915M 915MHz / 15MHz TT (22.8x7.6x12.5) Pin Type / Module Type
TT67218A1-915M 915MHz / 20MHz TT (22.8x7.6x12.5) Pin Type / Module Type
TT67218A-915M 915MHz / 20MHz TT (22.8x7.6x12.5) Pin Type / Module Type
915MHz / 20MHz TT (22.8x7.6x12.5) Pin Type / Module Type
915MHz / 30MHz TT (22.8x7.6x12.5) Pin Type / Module Type
915MHz / 55MHz TT (22.8x7.6x12.5) Pin Type / Module Type
915MHz / 55MHz TT (22.8x7.6x12.5) Pin Type / Module Type
915MHz / 80MHz TT (22.8x7.6x12.5) Pin Type / Module Type
TT67867B-915M 915MHz / 90MHz TT (22.8x7.6x12.5) Pin Type / Module Type
B. 4 Pole Filter  Spec (Freq / BW) Size (LxWxH)  Accepted Type
TF69248A-915M 915MHz / 15MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TF69218A1-915M 915MHz / 20MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TF69550F-915M 915MHz / 27MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TF69609A-915M 915MHz / 60MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TF64477F-915M 915MHz / 80MHz TF (30.5x7.6x12.5) Pin Type / Module Type
TF69861B-915M 915MHz / 120MHz TF (30.5x7.6x12.5) Pin Type / Module Type

We always support short lead time for standards unit delivery, also specs customizable service. In 1 to 2 week, you can obtain cost-effective Bandpass Filter as signal jamming solution for your wireless power transmitter and receiver designs. Customizable specs contains the center frequency (up to 60 GHz), bandwidth (up to 40 GHz), attenuation, insertion loss, return loss, package (pin, connector or smd), power (up to 200W average), impedance and so forth. Please feel free to Contact us for a specific, feasible and quality reliable RF Filter (bandpass, notch, bandstop, lowpass, highpass) and Duplexer, Splitter and Combiner and so forth.

All our products made in Taiwan, do not contain designated hazardous materials, compliance RoHS, REACH and ISO certificated. For more technical information (how to make calibration, how to tuning etc) and test reports, please visit: support

In finally, please feel free to contact us whenever wherever, if you have more questions how to solve or avoid signal jamming in RF circuits. TEMWELL will be always here to be your good RF & Microwave passive components supporter, from design, prototype, trial production, massive production and further technical consulting.