Tunable Notch Filter used for all existing mobile bands | Ranatec

Tunable Notch Filter

The Ranatec Tunable Band Reject Filters are critical tools for adaptation to stringent new ETSI/3GPP conformance test specifications for mobile device radio properties, that covers all sub-6 mobile bands and channel bandwidths for 2G/3G/4G/5G. Designed for formal conformance testing performed by accredited test houses, as well internal verification by mobile device vendors. A flexible and easy to use test automation platform to support almost any ambition level, tailored to your demands.

The Tunable Band Reject Filters are fully equipped for conformance testing across all existing mobile bands up to and including 6000 MHz. Filter characteristics are remained constant across the entire frequency range. A frequency extension unit is available as an option to complement the tunable band reject filters, extending the pass band up to 26.5 GHz.

Overview

Tunable Band Reject Filter

Available as the following versions:

Product Tunable center frequency Reject band 1 Reject band 2
RI 266 600-6000 MHz 5 MHz 100 MHz
RI 264 600-2700 MHz 5 MHz
RI 263 600-6000 MHz 100 MHz
RI 262 600-4200 MHz 100 MHz
RI 261 700-3800 MHz 20 MHz
RI 260 700-2700 MHz 20 MHz

RI 266

Combined 5 & 100 MHz Tunable Band Reject Filter

600-2700 & 700-6000 MHz

Features

  • Frequency tunable between 600 – 6000 MHz

  • 1 kHz center frequency resolution
  • 25 ppm frequency stability
  • 20 MHz reject bandwidth as standard *
  • 35 dB band reject depth as standard *
  • Filter characteristics can be selected in runtime **
  • 19”, 3 U rack mountable
  • Remote control via LAN
  • LabView drivers

* Other filter characteristics available on request

** Multiple filter characteristics available on request

Technical Data

Model Number Description Frequency bands for filter center frequency [MHz] Measurement bands [MHz] Filter bandwidth [MHz] Filter slopes [MHz]
RI 266 Combined 5 & 100 MHz tunable band reject filters 600-2700 & 700-6000 MHz 600-1000

1400-2000

2000-2700

700-1000

1400-2000

2000-2700

3300-4200

4400-5000

5150-5925

550-1600

1000-2400

1700-3000

600-1600

1000-2400

1700-3000

3200-4300

4000-5400

4925-6000

5

100

10

Ordering

  • RI 266 Tunable Band Reject Filter

  • RI 4276 Frequency Extension Box 26.5 GHz

Product Description

The RI 266 is fully equipped for conformance testing across all existing mobile bands. Narrow bands (1.4, 3 and 5 MHz bandwidth channels) are defined from 450 to 2 700 MHz, and broad bands (10, 15, 20, 25, 30, 40, 50, 60, 80 and 100 MHz bandwidth channels) are defined from 600 to 5000 MHz. In addition, there are 3GPP V2X channels of 10 and 20 MHz bandwidth from 5150 to 5925 MHz. Filter characteristics remain constant across the entire frequency range. A frequency extension unit is available as an option, extending the pass band up to 26,5 GHz.

Programmable attenuators are included at both input and output of the RI 266 in order to allow signal level settings for optimum performance.

The basic test set-up for Transmitter output spurious emissions verification is shown in the figure below.

Basic test setup for Transmitter putput spurious emissions

The mobile device under test can be set to transmit at any narrow band mobile channel and the RI 266 band reject filter programmed to suppress the transmitted signal at least 30 dB without impacting the level of any spurious emissions from the mobile device. As a result, the problem of the limited dynamic range of the spectrum analyzer is avoided.

To verify the receiver blocking characteristics of the mobile device under test, the basic test set-up looks as in the figure below.

Basic test setup for receiver blocking characteristics of the mobile device under test
In this case, the RI 266 band reject filter is centered at the channel frequency used for the link between the base station emulator and the device under test, while the interference signal is outside the rejection band of the RI 266. In doing so, any excessive noise at the channel frequency coming from the interference generator is suppressed, while the interferer itself is left unattenuated.

RI 264

5 MHz Tunable Band Reject Filter 600-2700 MHz

Features

  • Frequency tunable between 600 – 2700 MHz

  • 1 kHz center frequency resolution
  • 25 ppm frequency stability
  • 20 MHz reject bandwidth as standard *
  • 35 dB band reject depth as standard *
  • Filter characteristics can be selected in runtime **
  • 19”, 3 U rack mountable
  • Remote control via LAN
  • LabView drivers

* Other filter characteristics available on request

** Multiple filter characteristics available on request

Technical Data

Model Number Description Frequency bands for filter center frequency [MHz] Measurement bands [MHz] filter bandwidth [MHz] filter slopes [MHz]
RI 264 Tunable 5 MHz band reject filter 450-2700 MHz 600-1000

1400-2000

2000-2700

550-1600

1000-2400

1700-3000

5 1.4

Ordering

  • RI 264 Tunable Band Reject Filter

  • RI 4274 Frequency Extension Box 26.5 GHz

RI 263

100 MHz Tunable Band Reject Filter 600-6000 MHz

Features

  • Frequency tunable between 600 – 6000 MHz

  • 1 kHz center frequency resolution
  • 25 ppm frequency stability
  • 20 MHz reject bandwidth as standard *
  • 35 dB band reject depth as standard *
  • Filter characteristics can be selected in runtime **
  • 19”, 3 U rack mountable
  • Remote control via LAN
  • LabView drivers

* Other filter characteristics available on request
** Multiple filter characteristics available on request

Technical Data

Model Number Description Frequency bands for filter center frequency [MHz] Measurement bands [MHz] Filter bandwidth [MHz] Filter slopes [MHz]
RI 263 Tunable band reject filter 600-6000 MHz 700-1000

1400-2000

2000-2700

3300-4200

4400-5000

5150-5925

600-1600

1000-2400

1700-3000

3200-4300

4000-5400

4925-6150

100 10

Ordering

  • RI 263 Tunable Band Reject Filter

  • RI 4273 Frequency Extension Box 26.5 GHz

RI 262

100 MHz Tunable Band Reject Filter 600-4200 MHz

Features

  • Frequency tunable between 600 – 4200 MHz

  • 1 kHz center frequency resolution
  • 25 ppm frequency stability
  • 20 MHz reject bandwidth as standard *
  • 35 dB band reject depth as standard *
  • Filter characteristics can be selected in runtime **
  • 19”, 3 U rack mountable
  • Remote control via LAN
  • LabView drivers

* Other filter characteristics available on request

** Multiple filter characteristics available on request

Technical Data

Model Number Description Frequency bands for filter center frequency [MHz] Measurement bands [MHz] Filter bandwidth [MHz] Filter slopes [MHz]
RI 262 Tunable band reject filter 600-4200 MHz 600-700

700-1000

1400-2000

2000-2700

3300-3400

3400-3800

3800-4200

300-1100

600-1200

1200-2200

1700-3000

2700-4000

3100-4100

3500-4300

100 10

Ordering

  • RI 262 Tunable Band Reject Filter

  • RI 4272 Frequency Extension Box 26.5 GHz

RI 261

20 MHz Tunable Band Reject Filter 700-3800 MHz

Features

  • Frequency tunable between 700 – 3800 MHz

  • 1 kHz center frequency resolution
  • 25 ppm frequency stability
  • 20 MHz reject bandwidth as standard *
  • 35 dB band reject depth as standard *
  • Filter characteristics can be selected in runtime **
  • 19”, 3 U rack mountable
  • Remote control via LAN
  • LabView drivers

* Other filter characteristics available on request

** Multiple filter characteristics available on request

Technical Data

Model Number Description Frequency bands for filter center frequency [MHz] Measurement bands [MHz] Filter bandwidth [MHz] Filter slopes [MHz]
RI 261 Tunable band reject filter 700-3800 MHz 698-1000

1400-2000

2000-2700

3400-3800

600-1200

1200-2200

1700-3000

3100-4100

20 10

Ordering

  • RI 261 Tunable Band Reject Filter

  • RI 4271 Frequency Extension Box 26.5 GHz

RI 260

20 MHz Tunable Band Reject Filter 700-2700 MHz

Features

  • Frequency tunable between 700 – 2700 MHz

  • 1 kHz center frequency resolution
  • 25 ppm frequency stability
  • 20 MHz reject bandwidth as standard *
  • 35 dB band reject depth as standard *
  • Filter characteristics can be selected in runtime **
  • 19”, 3 U rack mountable
  • Remote control via LAN
  • LabView drivers

* Other filter characteristics available on request
** Multiple filter characteristics available on request

Technical Data

Model Number Description Frequency bands for filter center frequency [MHz] Measurement bands [MHz] Filter bandwidth [MHz] Filter slopes [MHz]
RI 260 Tunable band reject filter 700-2700 MHz 698-1000

1400-2000

2000-2700

600-1200

1200-2200

1700-3000

20 10

Ordering

  • RI 260 Tunable Band Reject Filter
  • RI 4270 Frequency Extension Box 26.5 GHz

Background

Connected devices and mobile applications require wireless network access that is resilient, secure and able to protect individuals’ privacy. For this reason, a massive number of harmonized standards and specifications have been developed by the wireless industry. Conformance to these standards and specifications is the way to accomplish resilient and secure wireless access.

More specifically, ETSI/3GPP has released an extensive conformance test specifications (TS 136 521-1 for LTE and TS 138 521-1 for 5G NR) that stipulate how and to what levels the radio properties of a mobile device should be verified in order to enable high quality wireless access. Two important objectives for the conformance test specification are to detail requirements applicable for any mobile device with respect to:

  • Transmitter output spurious emissions
  • Receiver blocking characteristics

(Receiver blocking characteristic is a measure of the receiver’s ability to receive a wanted signal in the presence of an unwanted interferer.)

Appropriate testing and conformance to these requirements are needed to safeguard the quality of the wireless access for an individual user as well as for the overall network performance.

In some cases, the performance requirements – and hence the test levels – are so stringent that the capabilities of conventional test instruments are not enough. This is in particular the case for commercially available:

  • Spectrum analyzers – that do not have the dynamic range needed to fully verify transmitter output spurious emissions
  • Signal generators – that exhibit too much broadband noise to adequately verify receiver blocking characteristics

To address this, Ranatec has developed the RI 266 – a state-of-the-art, programmable notch filter. The RI 266 extends the dynamic range in spurious emission measurements with at least 30 dB by selectively suppressing the wanted transmitted signal, while leaving the spurious outputs unaffected. Similarly, the RI 266 can be set up to lower the noise level at the wanted receive frequency from any signal generator with up to the same amount, thus enabling adequate verification of receiver blocking characteristics.

The RI 266 is intended for both formal conformance testing, performed by accredited test houses, as well internal verification by mobile device vendors.

Typical Test Setup

For the purpose of doing conformance testing of mobile devices, a generic, automated test set-up is typically established.

Tunable Notch Filter Generic test setup

The Signaling units emulates the Radio Access Network base stations / access points in both downlink and uplink. A set of standard lab instruments (typically power meters, a spectrum analyzer and a signal generator) are required for calibration of the various signal paths as well performing some of the actual measurements. All these parts of the generic test set-up are typically supplied by the tier 1 players within wireless test equipment (Anritsu, Keysight or Rohde & Schwarz).

At the center of this generic test set-up sits the parts supplied by Ranatec:

  1. Signalling Selection and MIMO Multiplexing contains the programmable switches, couplers and attenuators needed to accommodate the adequate signal constellation in both uplink and downlink
  2. Signal Routing is the core of the test automation and provides flexible routing and level setting across the test system, by means of programmable switches, couplers and attenuators
  3. Frequency Extension contains switchable high-pass and low-pass filters to allow for spurious emission measurements over the entire frequency range up to 26.5 GHz
  4. Programmable Notch Filter refers to the Ranatec RI 26X family of tunable band reject filters
  5. DUT and MIMO Multiplexing is the correspondence of the Signalling Selection and MIMO Multiplexing and provides and adequate signal constellation in both uplink and downlink to/from the devices under test

The actual test set-up depends on the overall ambition in terms of coverage of standards and frequency bands, type and number of DUT:s used, the selection of signaling units and lab instrumentations – as well as the ambition level in terms of level of automation. Ranatec has developed a flexible and easy to use test automation platform to support almost any ambition level, tailored to the customer demands. The key component in any such set-up is the RI26X family of programmable notch filters.

An example of such a test set-up is shown in the picture below.

Tunable Notch Filter test setup

FAQs

A notch filter is a filter used to remove a specific frequency. A tunable notch filter has the feature that the center frequency of the notch can be set at different values, either mechanically or electronically.

A band-reject filter is a filter used to remove a frequency band. A tunable band rejects filter has the feature that the center frequency of the band can be set with different values, either mechanically or electronically.

A tunable band rejects filter gives high flexibility and precision. The alternative to a tunable band reject filter is typically a large amount of fixed filters and switches. To be able to test all frequencies, 2G, 3G, 4G, 5G, WiFi, and Bluetooth, hundreds of fixed filters are needed.

Most Tunable Band Reject Filters are mechanical. The Ranatec’s Tunable Band Reject Filter is digital, which means the center frequency can be changed within a microsecond. The Ranatec Tunable Band Reject Filter, due to its digital design, is faster, more precise, more convenient, and has a longer lifetime, than mechanical versions.

Ask for a Quote