Frequently Asked Questions

TTE Frequently Asked Questions (FAQ)

For urgent assistance or if you cannot find the answer to your question below, please feel free to e-mail us at sales@tte.com or call us at (+1) 716-532-2234. We will be more than happy to assist you. Please also reference our Resources page that contains additional information on our Filter offerings and other Technical documents.

General FAQ

TTE has been manufacturing custom filters in the USA since 1956 and has particular expertise in short lead times.  Typical lead time is 2 weeks but expedited lead time as short as 3-5 days is available on many built-to-order designs. In response to customers requiring immediate delivery, TTE offers the LC9S Series of Lowpass Chebyshev Filters from stock for same-day shipment – when 3 to 5 days is not fast enough. This 9-pole series provides twelve distinct part numbers, each at a specific -1dBc passband frequency, from 30 MHz to 6 GHz. Complete technical information is available at the LC9S product page. Check our Product from Stock page for updates regarding products available from inventory.

Upon request, test plots or filter simulation data will be provided at no charge per typical performance of a previously tested design or via theoretical simulation of a new design.

The sales department will respond to your request in a timely manner and will provide a price and delivery quotation, as well as a specification, for each line item.

No, samples are not available. TTE filters are designed and manufactured to order.

Generally, the power into the filter load ranges from 20 mW to 1 W, however it is frequency dependent. A 100 Hz bandpass filter will saturate at low power while microwave filters are able to handle much higher power levels. Please consult technical support for your individual specification.

Test data is provided with all shipments. Upon request, test plots or filter simulation data will be provided at no charge per typical performance of a previously tested design or via theoretical simulation of a new design.

Test data is provided with all shipments. Upon request, test plots or filter simulation data will be provided at no charge per typical performance of a previously tested design or via theoretical simulation of a new design.

Yes. Our website is secure. Security remains a primary concern of our company. The TTE website implements Secure Sockets Layer (SSL) Certificates which enables the encryption of all sensitive information during online transactions. For more information on our SSL Certificates, contact our WebMaster at webmaster@tte.com.

Ordering Procedure
K C 4 T R -100 M -10 P -50 -720 A
1 2 3 4 5 6 7 8 9 10 11 12
  1. “K” = Bandpass, “L” = Lowpass, “H” = Highpass, “R” = Band Rejection (Notch)
  2. “T” = Bessel, “B” = Butterworth, “C” = Chebyshev, “E” = Elliptical, “G” = Gaussian
  3. * The number of poles in the filter, or the filter order.
  4. Adding a “T” to the part number designates a low THD filter
  5. Add an “R” to the part number designates a RoHS Compliant filter.
  6. The center frequency of the filter.
  7. “G” = GHz, “M” = MHz, “K” = kHz, Blank = Hz
  8. ** Bandwidth of the filter, can be expressed in frequency or percentage.
  9. ** “P” = Percentage, “G” = GHz, “M” = MHz, “K” = kHz, Blank = Hz
  10. Termination Impedance
  11. *** The case part number
  12. “A” = SMA, “B” = BNC, “N” = Type N, “K” = 2.92mm, “V” = 1.85mm
Notes:
For Elliptical Bandpass Filters: Replace 1, 2 & 3 with Q40 (4th Order) or Q70 (7th Order)
* Elliptical Lowpass and Highpass filtres will have additional numbers.
** Not used for lowpass and highpass filters *** Not used for custom housings.
304R-3G-5P-A
1234567
  1. * The last two numbers indicate the number of poles, or the filter order.
  2. Adding an “R” to the part number designates a RoHS Compliant filter.
  3. The center frequency of the filter.
  4. “G” = GHz, “M” = MHz
  5. ** Bandwidth of the filter, can be expressed in frequency or percentage.
  6. ** “P” = Percentage, “G” = GHz, “M” = MHz, “K” = kHz, Blank = Hz
  7. “A” = SMA, “B” = BNC, “N” = Type N, “K” = 2.92mm, “V” = 1.85mm

Notes:
* Replace with 315P for our standard 1.5% bandwidth combline filter series.
** Not used for 315P series

PRODUCT PAYMENT AND TERMS

No. COD orders are not accepted at TTE.

TTE accepts payments by electronic transfer, check, money order or major credit card. Purchase orders are accepted on credit approval. Open accounts can be established upon request. Credit cards are charged at the time of shipment.

To establish an account, TTE requires three supplier references and a bank reference. By supplier, we mean a normal source of materials used by your company in the manufacture of your products. In terms of the bank reference, your company will need to authorize a representative of the bank to release information to TTE.

TTE is well aware of the need for timely deliveries. To support its customers TTE maintains a large inventory of standard materials which enables the company to deliver most of its products within 2 weeks. Expedited lead times of 3-5 days are available on many products. Some products are available for immediate delivery from stock.

TTE Filters utilizes a variety of shipping services to deliver product to customers depending on final destination, shipment weight, delivery timing and other customer-specific requirements. Options include ground transportation, air transportation, and overnight/courier service. Additional charges may apply. Shipment dates are approximate and based upon Seller’s best judgements and are subject to factory schedules and production limitations. Seller can assume no liability, consequential or otherwise, of any sort or nature, resulting from any delay caused by act of God, fire or other casualty, accident, strike, or other cause beyond Seller’s control. Lost shipments will not be replaced until freight carrier in writing authorizes the replacement at their expense.

FILTER CANCELLATIONS AND INCORRECT ORDERS

TTE filters are manufactured to the customer’s specification, and thus, are not returnable.

As part of the manufacturing process the circuit is epoxy-encased and therefore not adjustable.

Orders cannot be cancelled, or changed, once they have been accepted by TTE.

Prior to returning products thought to be deficient, a Return Material Authorization must be issued by TTE to the Buyer. No returns of product will be accepted unless the factory has been contacted and a Return Material Authorization number has been issued. The RMA number must be accompanied by a material discrepancy report and test data. A fee to cover the analysis costs on the returned components under this warranty will be charged to the buyer if, when after examination by TTE, the products are found to meet the specifications or have failed for reasons not covered by this warranty.

BANDPASS FILTERS FAQ

  • Bessel Filters – exhibit a constant time delay in the passband of the filter.
  • Butterworth Filters – are more selective than Bessel Filters and offer both monotonic passbands and monotonic stopbands.
  • Chebyshev Filters – have low ripple passbands and monotonic stopbands. The passband ripple is ±0.25 dB typical.
  • Combline Filters – are Chebyshev topology and have low ripple passbands and monotonic stopbands. The passband ripple is ±0.25 dB typical.
  • Combline 315P Filter – is from the Combline family and has a specific passband bandwidth of 1.5% Fo.
  • Elliptical Function Anti-Aliasing Filters – offer better selectivity than Chebyshev Filters. Passband ripple is ±0.25 dB typical. These filters exhibit poles and zeros in the stopband that are below the specified rejection level.
  • Gaussian Filters – are designed to pass a step function with zero overshoot and minimum rise. Similar to Bessel Filters they offer limited selectivity.

CAPACITOR FAQ

Instec filters are manufactured using MLC discoidals.  These robust capacitors provide optimum filtering and are preferred when compared to chip or leaded MLC capacitors and tubular capacitors .  MLC discoidal caps have multiple electrodes and offer extremely low impedance due to the through-hole design of the discoidal cap providing infinite paths to ground.  The discoidal design offers significantly lower inductance than leaded capacitor filters, lower impedance paths to ground than chip capacitor filters, and are much more robust in design than tubular capacitor filters.  Discoidal caps design also effectively prevents radiation from the input coupling directly with the output of the capacitor, unlike leaded or chip capacitors used as filters. The combination of low impedance, low inductance, and input/output isolation provides excellent shunting of EMI for frequencies up to and beyond 1 GHz.

Instec discoidal caps also give the following advantages:

  • Highest capacitance to volume ratio of the filter caps mentioned above.
  • Lowest impedance at higher frequencies.
  • Superior strength to tubular capacitors under both mechanical and thermal stresses.

Instec offers filters in various configurations as well as custom solutions.  Selection of the proper filter for the application is key to achieving the best overall performance.  Our design and technical teams are available to assist in this selection.

EMI/RFI FAQ

Instec Hermetic filters utilize glass seals to achieve hermeticity and are ideal for applications where rugged, sealed filters are required. Internal designs consist of combinations of capacitors and inductors (ferrite beads or wire-wound inductors) in ¼-28 or 5/16-24 threaded cases. Given their larger sizes, very high capacitances can be achieved and higher current ratings are possible. Filter performance can be tuned to match the application by choice of inductors.

Filter plates, custom assemblies, and solutions: Instec designers can work with your engineers to design custom solutions or to give you outsourcing options for your filter assemblies.

Instec Resin Sealed filters offer a wide variety of packages and sizes.  These range from gold plated solder-in filters (610 Series) to 12-32 thread silver plated  bolt filters (650 Series).  The solder-in filters offer very low profile and narrow diameter filtering and are ideal for multi-circuits or filter plates where tight spacing is required.  If the filters are to be used in a filter plate, Instec has a fine-tuned assembly process that can be used to assemble your filter plates.  We are also set up to do 100% electrical screening and visual inspection on filter plates so your assembly yields would be pushed back to Instec.

The various sizes of bolt filters are ideal where higher current ratings are required or where inductive elements need to be introduced to the filter. All bolt filters ship with the required mounting hardware.

Note re. 610 Series solder-in filters:  Instec solder-in filters have a hermetic seal on one side and the discoidal is soldered 360˚ around the OD.  This combination, in effect, gives a hermetic seal with the chassis, wall or plate.

HIGHPASS FILTERS FAQ

  • Butterworth Filters – offer both monotonic passbands and monotonic stopbands.
  • Chebyshev Filters – have low ripple passbands and monotonic stopbands. The passband ripple is ±0.25 dB typical.
  • Elliptical Function Filters – offer better selectivity than Chebyshev Filters. The passband ripple is ±0.25 dB typical. These filters exhibit poles and zeros in the stopband that are below the specified rejection level.
  • TTE Designed Filters – are similar to Elliptical Function Filters. They exhibit both passband and stopband ripple. The passband ripple is ±0.25 dB typical.

LOWPASS FILTERS FAQ

  • Bessel Filters – exhibit a constant time delay in the passband of the filter.
  • Butterworth Filters – are more selective than Bessel Filters and offer both monotonic passbands and monotonic stopbands.
  • Chebyshev Filters – have low ripple passbands and monotonic stopbands. The passband ripple is ±0.25 dB typical.
  • Chebyshev High-Power Filters – provide power handling up to 300 Watts and frequency range from 600 kHz to 600 MHz.
  • Chebyshev LC9S Filters (from Stock) – this series is offered from stock for off-the-shelf convenience; a recent expansion of the product line to 12 parts provides frequencies from 30 MHz to 6 GHz.
  • Elliptical Function Filters – offer better selectivity than Chebyshev Filters. The passband ripple is ±0.25 dB typical. These filters exhibit poles and zeros in the stopband that are below the specified rejection level.
  • Elliptical Function Anti-Aliasing Filters – exhibit both passband and stopband ripple. The passband ripple is ±0.25 dB typical.
  • Gaussian Filters – are designed to pass a step function with zero overshoot and minimum rise. Similar to Bessel Filters they offer limited selectivity.
  • TTE Designed Filters – are similar to Elliptical Function Filters. They exhibit both passband and stopband ripple. The passband ripple is ±0.25 dB typical.

Multiplexer Faq

Multiplexers and diplexers are available for any frequency from 10 kHz to 26 GHz, with specials to 40 MHz. High-power networks to 600 Watts as well as ground-based and airborne versions are available. Airborne diplexers are available with power handling capabilities up to 75 Watts. Connectors and gender are customer-specified.

Applications for multiplexers or other networks include telemetry, up/down converters, combining or splitting base stations, connections to a common antenna, and many more.

These products are manufactured in CNC-machined housing that is individually designed to accommodate the customer’s circuit requirements.

Lead time varies for these products from two to eight weeks.

NOTCH FILTERS FAQ

  • Butterworth Filters – offer monotonic passbands.
  • Chebyshev Filters – have a low ripple passband of ±0.25 dB typical.
  • Elliptical Function Filters – have a passband ripple of  ±0.25 dB typical. These filters are more selective than Butterworth or Chebyshev topologies