Pass/Reject FiltersBPBR 2/3 / BRBP 2/3

Band-Pass/Band-Reject Filters for the 160 MHz Band

Description

  • The BPBR 2/3… and the BRBP 2/3… are 3-cavity pass-reject filters, which pass one frequency or frequency band and reject another in immediate vicinity of the pass frequency.
  • The filters are delivered in two basic models: The BPBR-types have the reject range on the high side of the pass frequency and the BRBP-types have the reject range situated on the low side of the pass frequency.
  • These filter types can be used to protect a receiver against interference from a nearby transmitter. The filters are tuned to reject the interfering signal. Pass-reject-type filters are applied when the spacing between the utility signal and the interfering signal is so small, that the slope steepness of normal band-pass filters or notch filters are not sufficient enough to provide adequate rejection.
  • These filters are primarily intended to pass and reject two single frequencies, but the filters can also be tuned to pass and reject several single frequencies or to having a certain pass and reject port bandwidth. In these cases, factory-tuning is recommended.
  • Both the BPBR 2/3… and the BRBP 2/3… are delivered in a high-band and a low-band version tunable within 136 - 154 and 152 - 175 MHz, respectively. These models are again divided into submodels, each dedicated to work with a certain spacing between the pass frequency and the reject frequency. See “Ordering information” below.
  • The filter has very small physical dimensions owing to the use of high-Q, temperature compensated helical resonators.
  • The housing is made of extruded aluminium, the chassis of passivated steel, and teflon insulation has been applied in the rigid coaxial cables and in the connectors.
  • The filter is black vinyl coated to prevent corrosion.

Specifications

Electrical
Model BPBR 2/3 / BRBP 2/3
Filter Type Band-Pass / Band-Reject Filters
Frequency 136 - 175 MHz
Max. Input Power 50 W
Pass Band Insertion Loss Single-channel tuned: < 1.0 dB
Multi-channel tuned 1.5 MHz BW: < 1.2 dB
(at 4.5 MHz spacing)
Impedance 50 Ω
Pass-Reject Spacing 4 - 10 MHz (see table)
Reject Attenuation Single channel tuned: > 75 dB
Multi channel tuned 1.5 MHz BW: > 50 dB
VSWR < 1.5:1
Mechanical
Connection(s) BNC(f)
Dimensions 163 x 77 x 33 mm / 6.42 x 3.03 x 1.30 in.
Weight Approx. 0.38 kg / 0.84 lb.
Environmental
Operating temperature range -30 °C to +60 °C
Frequency Stability Approx. 5 ppm / °C

Diagram and Mounting

TYPICAL RESPONSE CURVES

TYPICAL RESPONSE CURVES,

Ordering Designations

Model Product No. Description Frequency
BPBR 2/3L-4/6 200001312 SPACING: 4 - 6 MHz 138 - 156 MHz
BRBP 2/3L-4/6 200001451 SPACING: 4 - 6 MHz 138 - 156 MHz
BPBR 2/3L-6/8 200001310 SPACING: 6 - 8 MHz 138 - 156 MHz
BRBP 2/3L-6/8 200001453 SPACING: 6 - 8 MHz 138 - 156 MHz
BPBR 2/3L-8/10 200001311 SPACING: 8 - 10 MHz 138 - 156 MHz
BRBP 2/3L-8/10 200001454 SPACING: 8 - 10 MHz 138 - 156 MHz
BPBR 2/3H-4/6 200001304 SPACING: 4 - 6 MHz 152 - 175 MHz
BRBP 2/3H-4/6 200001444 SPACING: 4 - 6 MHz 152 - 175 MHz
BPBR 2/3H-6/8 200001305 SPACING: 6 - 8 MHz 152 - 175 MHz
BRBP 2/3H-6/8 200001448 SPACING: 6 - 8 MHz 152 - 175 MHz
BPBR 2/3H-8/10 200001307 SPACING: 8 - 10 MHz 152 - 175 MHz
BRBP 2/3H-8/10 200001449 SPACING: 8 - 10 MHz 152 - 175 MHz

Ordering information

If pass and reject frequencies are stated when ordering, the filters are delivered factory-adjusted. Ordering example: BRBP 2/3…, LOW: 149.5 MHz, HIGH: 154.0 MHz. In this case, further information is not required.

When ordering untuned filters please use the model selection table above to select the appropriate ordering designation for the desired filter type.