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R. A. Wood Associates has designed and built a new wide-band digital attenuator amplifier (DAA), using surface mount technology. The DAA can be utilized across the frequency band: 0.5 - 18.0 GHz. This product is an ideal choice for Electronic Warfare (EW) applications in high dynamic range locations. This unit has good wide-band flatness, high dynamic range, and good noise figure for its high 1dB compression point. Performance in narrower bands is even better, as shown in the specification table and its plots. To see digital attenuation accuracy data over various frequency bands, please see the attenuation table. We are keeping these built ahead to improve the delivery time. If you are interested in pricing and delivery, please contact us.
| The wide-band performance of the RCT0061 WB Digital Attenuator Amplifier can be seen in the plots below. The plots display typical measured data for various parameters such as gain (S21), output 1dB compression point (P1dB), input return loss (S11) and output return loss (S22). The unit is designed to be supplied with +12V, and -12V on their respective pins. All data on this page was taken with the unit at these voltages. Typical current draw for the positive voltage is approximately 240mA, and typical current draw for the negative voltage is approximately 20mA. These DAA units can be built quickly with surface mount assembly. |  |
Typical Gain and Noise Figure across the DAA's working band can be seen below.
Typical output 1dB compression points across the unit's working band is plotted below.
Typical input and output return loss across the frequency band can be seen below.
The table below shows typical, and worst case data for the RCT0061 Digital Attenuator Wide-Band Amplifier. The data below also shows the unit's performance in its reference state, providing TTL logic HIGH to pins A0-A3. Input and output return loss (S11 and S22) values are representative of the maximum values over the various frequency bands. The P1dB value is representative of the minimum value over the various frequency ranges, and is associated with the output. Peak to peak (P-P) value is the difference, in decibels, between the positive and negative peak of the measured gain value. "NF" refers to the noise figure maximum for each respective band. Links show typical data plots.
| Frequency Range (GHz) | |||||||||
| Specification | 0.5 - 2.0 | 2.0 - 4.0 | 4.0 - 8.0 | 8.0 - 12.0 | 12.0 - 18.0 | 0.5 - 18.0 | 2.0 - 18.0 | ||
| GainAvg. (dB) | Min. | 17.4 | 17.1 | 16.1 | 16.1 | 15.7 | 16.2 | 16.1 | |
| Typ. | 17.5 | 17.2 | 16.4 | 16.5 | 16.3 | 16.6 | 16.5 | ||
| Max. | 18.0 | 17.7 | 16.9 | 16.9 | 16.8 | 17.1 | 17.0 | ||
| P-P Flatness (dB) | Min. | -- | -- | -- | -- | -- | -- | -- | |
| Typ. | 0.9 | 0.7 | 0.7 | 0.8 | 0.9 | 2.3 | 1.8 | ||
| Max. | 1.0 | 0.8 | 1.0 | 0.9 | 1.9 | 3.6 | 2.9 | ||
| P1dB Min. (dBm) | Min. | 23.1 | 23.6 | 23.3 | 21.7 | 17.6 | 17.6 | 17.6 | |
| Typ. | 24.4 | 24.5 | 24.8 | 24.1 | 18.8 | 18.8 | 18.8 | ||
| Max. | -- | -- | -- | -- | -- | -- | -- | ||
| S11Max (dB) | Min. | -- | -- | -- | -- | -- | -- | -- | |
| Typ. | -14.1 | -14.1 | -16.4 | -12.7 | -12.2 | -12.2 | -12.2 | ||
| Max. | -10.2 [1.9:1] | -10.2 [1.9:1] | -10.2 [1.9:1] | -9.5 [2.0:1] | -9.5 [2.0:1] | -9.5 [2.0:1] | -9.5 [2.0:1] | ||
| S22Max (dB) | Min. | -- | -- | -- | -- | -- | -- | -- | |
| Typ. | -19.6 | -17.7 | -16.6 | -14.7 | -13.0 | -13.0 | -13.0 | ||
| Max. | -11.7 [1.7:1] | -11.7 [1.7:1] | -11.7 [1.7:1] | -9.5 [2.0:1] | -9.5 [2.0:1] | -9.5 [2.0:1] | -9.5 [2.0:1] | ||
| NFMax. (dB) | Min. | -- | -- | -- | -- | -- | -- | -- | |
| Typ. | 7.3 | 5.5 | 5.2 | 6.3 | 8.4 | 8.4 | 8.4 | ||
| Max. | 8.0 | 6.5 | 6.5 | 7.5 | 9.5 | 9.5 | 9.5 | ||
Typical Relative Attenuation across the DAA's working band can be seen below.
The functionality of the digital attenuation portion of the unit is done via TTL or LVTTL logic provided to the four control pins. We ensure the product's digital attenuation states meet a window of accuracy acceptable to its current applications. For attenuation states less than 7 dB, we expect a maximum value of 0.3 + 4% of the desired attenuation setting. For states greater than 7 dB, we expect a maximum value of 0.3 + 8% of the desired attenuation setting.
Relative values are calculated point by point across the band, taking the reference state data and comparing it to the selected attenuation state. For example, with the 2 dB attenuation state selected, we ensure the unit has a gain level within 0.38 dB of the expected attenuation level. Additionally, if we have 16 dB gain in the reference state, we expect the unit to output 14 dB gain levels across its working frequency band in the 2 dB attenuation state.
Testing of these units involves recording maximum and minimum relative gain values in the selected attenuation state. The data presented in the table shows typical and worst case values of the various attenuation states the DAA offers. Selecting any of the links within the typical rows will load the appropriate plot. Each plot shows typical data across the desired band, along with maximum and minimum possible values to expect for each attenuation setting.
| Frequency Range (GHz) | |||||||||
| Relative Attenuation | 0.5 - 2.0 | 2.0 - 4.0 | 4.0 - 8.0 | 8.0 - 12.0 | 12.0 - 18.0 | 0.5 - 18.0 | 2.0 - 18.0 | ||
| 1 dB | Typical | 0.07 | 0.14 | 0.03 | 0.11 | 0.13 | 0.05 | 0.06 | |
| Maximum | 0.34 | 0.34 | 0.34 | 0.34 | 0.34 | 0.34 | 0.34 | ||
| 2 dB | Typical | 0.05 | 0.13 | 0.05 | 0.09 | 0.06 | 0.04 | 0.05 | |
| Maximum | 0.38 | 0.38 | 0.38 | 0.38 | 0.38 | 0.38 | 0.38 | ||
| 4 dB | Typical | 0.09 | 0.17 | 0.02 | 0.05 | 0.09 | 0.06 | 0.06 | |
| Maximum | 0.46 | 0.46 | 0.46 | 0.46 | 0.46 | 0.46 | 0.46 | ||
| 8 dB | Typical | 0.06 | 0.19 | 0.05 | 0.21 | 0.26 | 0.10 | 0.12 | |
| Maximum | 0.94 | 0.94 | 0.94 | 0.94 | 0.94 | 0.94 | 0.94 | ||
| 15 dB | Typical | 0.12 | 0.33 | 0.08 | 0.37 | 0.42 | 0.18 | 0.21 | |
| Maximum | 1.50 | 1.50 | 1.50 | 1.50 | 1.50 | 1.50 | 1.50 | ||
R. A. Wood Associates reserves the right to make minor modifications to limits if needed, to allow for producibility and manufacturing yields. In general, electrical performance improves as design improvements are learned and incoporated. If you would like to be notifed of limit changes, please contact us, and we will keep you informed. Thank you for your time and consideration, we hope to hear from you soon!
