Δέκτης γενικής χρήσης COLLINS 95S-1(A)

Introduction
The 95S-1A is a rack-mounted, high-performance receiver designed for general purpose usage in narrow-band radio applications. The receiver provides 0.005- to 2000-MHz frequency coverage and features software-based, state-of-the-art digital signal processing (DSP). The modern homodyne architecture and spurious-free MFD synthesizer provide the high performance necessary for demanding communications and surveillance applications. A serial control interface allows control via RS-232/422/485. The receiver draws less than 22 watts from an internal ac power supply or external 9 to 16 V dc.
Features
0.005- to 2000-MHz continuous coverage in 1-Hz increments.
16-bit DSP.
Full function programmability including: frequency, BFO, bandwidth, sweep, AGC, squelch, volume, demodulation, and calibration.
Selectable digital l/Q output (16 bits).
Standard AM, FM, CW, USB, LSB, and ISB modes.
Seventy-four standard bandwidths selectable from 0.1 to 300 kHz, plus five user-defined downloadable filters.
Spurious-free homodyne and MFD synthesizer circuit architectures.
Dual DSP filtering, demodulation, and processing with programmable demodulation selection and output combining.
Open architecture system: nonproprietary interface specifications are provided, allowing third party customization to any application.
Packaged in a single rack unit chassis (1.72 inches high, 19 inches wide).
RS-232/422/485 serial control.
Applications
The 95S-1A receiver is an excellent choice for any application requiring computer-controlled tuning of narrow-band radio signals. Several applications include:
Standard communications modes in the HF, VHF, and UHF bands (ie, AM, FM, CW, SSB) for civil, government, and military networks.
Test equipment.
Spectrum monitoring systems.
The Rockwell Collins 95S-1A general purpose receiver provides high performance at low cost and supports a wide variety of radio receiving applications. The 0.005 to 2000 MHz receiver is designed to satisfy user needs for applications ranging across commercial, government, and military communications, spectrum surveillance and test systems. It is suitable for fixed station, shipboard, or transportable environments.
The receiver serial command protocol is simple and yet minimizes the amount of data that must be transferred between the receiver and the controller. The protocol supports single command operations or can be operated in a multiple command mode that allows a sequence of commands to be executed in succession.
Rockwell Collins has planned the 95S-1A receiver to be an open architecture system, meaning that nonproprietary interface specifications are provided to users, allowing third party customization. Specifically, the memory in the receiver may be altered to download user-written DSP software and alternate control languages. The core Rockwell Collins DSP routines are non-alterable, but may be utilized or supplemented.

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Block Diagram...

Receiver Control Screen...

95S-1(A) SPECIFICATIONS

Frequency range ............. 0.005 to 2000 MHz

Frequency resolution ........ 1 Hz

Tuning time ................. 13 ms (typical), with AGC disabled

Frequency setability ........ +0.1 PPM, using electronic adjustment
                              of the internal standard

Frequency accuracy .......... +1 PPM, 0 to 50 ψC

Synthesizer noise ........... Characterized in the following table:

                               Frequency       Noise Power   Noise Power
                               Separation      @fo=100 MHz   @fo=1000 MHz

                              10 Hz           -55 dBc/Hz    -40 dBc/Hz
                              100 Hz          -90 dBc/Hz    -75 dBc/Hz
                              1 kHz           -105 dBc/Hz   -94 dBc/Hz
                              10 kHz          -110 dBc/Hz   -94 dBc/Hz
                              100 kHz         -135 dBc/Hz   -120 dBc/Hz
                              >1 MHz          -145 dBc/Hz   -140 dBc/Hz
Noise figure
  0 to 30 MHz antenna ....... 14 dB (typical)
  20 to 2000 MHz antenna .... 12 dB (typical)

External standard in ........ 1, 5, and 10 MHz

External standard level ..... 0 dBm (typical)

BFO ......................... 1-Hz step, range of +/-4 kHz

Serial control

  Interface ................. RS-232/RS-422/RS-485

  Data rate ................. 75 to 38,400 bits per second

  Format .................... 8 data bits or 7 data bits with 1 parity bit

Internal preselector ........ 20 to 2000 MHz (Dual conversion used for
                              frequencies below 20 MHz)

Demodulation modes .......... CW, SSB, ISB, AM, FM, I/Q

Carrier operated relay ...... Standard

AM sensitivity .............. 30% amplitude modulation at 400 Hz with
                              bandwidth of 6.4 kHz for 10 dB (s+n)/n

  0.1 to 30 MHz ............. 3 uV
  >30 MHz.................... 2 uV

FM sensitivity .............. SINAD of 12 dB with bandwidth of 12.8 kHz

  2 to 30 MHz ............... 1.1 uV
  >30 MHz.................... 0.5 uV
 
SSB/ISB/CW sensitivity ...... SINAD of 10 dB with bandwidth of 3.2 (1.6
                              CW) kHz and the input signal tuned 400 Hz
                              from the dial frequency

  0.005 MHz.................. 13uV (typical)
  >0.1 MHz................... 0.4 uV

Second order input intercept
  <30 MHz ................... +80 dBm (typical)
  >30 MHz.................... +60 dBm (typical)

Third order input intercept
  <30 MHz.................... +25 dBm (typical)
  30 to 500 MHz ............. +7 dBm (typical)
  >500 MHz .................. 0 dBm (typical)

Image rejection ............. >100 dB

IF rejection

  <30 MHz ................... >80 dB
  >30 MHz ................... >100 dB

Internal spurious ........... Less than equivalent antenna input
                              of -115 dBm

Conducted LO at antenna ..... <-110 dBm

Manual gain control ......... 1 dB increments

  <30 MHz ................... 144 dB range
  >30 MHz ................... 126 dB range

AGC range ................... +/-1.5 dB at audio output, with input
                              signal level range from 10 dB above
                              noise floor to 0 dBm

AGC programmability ......... AGC attack, hang, and decay time and
                              threshold values

Standard IF bandwidths ...... 74 programmable between 100Hz and 300kHz

Maximum input level

  Operating
    <30 MHz ................. +10 dBm
    >30 MHz ................. 0 dBm

  Nonoperating
    <30 MHz ................. +43 dBm
    >30 MHz ................. +33 dBm

Signal strength accuracy .... +/-2 dB over 0.1 to 2000 MHz frequency range

Postdetection audio filter .. Software selectable low-pass filters:
                               4.0 kHz, 25 kHz, 50 kHz, or bypass

Primary antenna input ....... 50 ohms impedance, VSWR <3:1; usable over
                              input frequency range of 2 to 2000 MHz, with
                              degraded performance below 30 MHz, compared
                              to HF antenna input

HF antenna input ............ 50 ohms impedance, VSWR <3:1; usable over
                              input frequency range of 0.005 to 30 MHz

HF antenna output ........... 50 ohms impedance, internally connected to
                              the primary antenna input when tune frequency
                              is below 30 MHz

Phone A&B out ............... 0.5 volt RMS into 100 ohms (max), 1% THD

Line A&B out ................ 0 dBm, 600 ohms (nominal)

Speaker A or B or A+B out ... 1 watt (max), 8 ohms, <10% THD

Input power ................. 9 to 16 V dc, 22 watts 85 to 240 V ac,
                              47 to 440 Hz

Mechanical

Packaging ................... EIA 1U rackmount, 1.72 in (43.6 mm)
                              H x 19 in (483 mm) W x 14.75 in (375 mm) D

RF connectors ............... BNC

Audio connector ............. DB1 5F

RS-232 connector ............ DB9F

Weight ...................... Approx 9.0 Lb (4.8 kg)

Operating temperature ....... 0 to 50 ψC

Storage temperature ......... -55 to +70 ψC

Humidity .................... 95% noncondensing

Shock ....................... Bench handling

Altitude .................... <10,000 ft

Cooling ..................... Convection

Specifications subject to change without notice.

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Under the hood...

TECHNICAL DESCRIPTION

The 95S-1(A) receiver is a 0.005 to 2000 MHz high-performance modular receiver employing a direct conversion (homodyne) architecture. The receiver frequency scheme uses only one mix: a single synthesizer local oscillator tuned to the desired signal frequency converts a signal directly to baseband, or the zero-frequency "IF signal." Baseband signal waveforms are filtered and demodulated under the control of digital signal processor (DSP) technologies developed and patented by Rockwell Collins. The advantages realized with a homodyne, or direct conversion receiver (DCR) architecture are simplicity and performance. The DCR provides wide frequency coverage without spurious-generating multiple mixes, and allows receiver selectivity to be obtained using audio low-pass filters rather than the more complex RF/IF filtering required with heterodyne receivers. Additionally, a majority of receiver gain can be applied at baseband rather than in front end RF stages. Because a DCR has no "IF," there is no receiver performance degradation due to "IF" or image rejection. Similarly, there are no "crossover" spurious responses because there is only a single local oscillator.
The 95S-1(A) incorporates a high-dynamic range Rockwell Gallium Arsenide mixer, preceded by internally tracking preselectors over the 20 to 2000 MHz portion of the tuning range. The receiver utilizes a hybrid architecture for frequencies within the 0.005 to 30 MHz tuning range, with parametric upconversion to a 51.2 MHz IF frequency.
An MFD synthesizer with progressive modulo-2 division provides quadrature low-noise, spurious-free injection signals to the HF and VHF/UHF mixers. The quadrature channels are identically low-pass filtered, amplified (with AGC), and digitized by a sigma-delta ADC.
The DSP section utilizes twin 16-bit microprocessors to perform all Finite Impulse Response (FIR) filtering, demodulation, automatic gain control (AGC), and ancillary functions for the receiver. An additional microprocessor provides communications and command execution control. A complement of standard DSP functions is contained within a flash memory integrated circuit, allowing field upgrades and customization. Seventy-four filter bandwidths are standard, and five optional user-defined filter coefficient sets can be transferred to the receiver for specialized applications. Software support and documentation, for developing user-defined FIR filter coefficients for use with the 95S-1(A) receiver, may be purchased from Rockwell Collins or can be developed using standard FIR filter design tools. Two independent demodulators may be operated simultaneously.
Audio output is generated by twin DACs, using any combination of demodulated signals, routed through selectable low-pass filters, and applied to headphone, line, and speaker amplifier circuits.
Digital 16-bit I/Q output is also available with user selectable pickoff points in the DSP signal flow.
All parameters and command settings are preserved in nonvolatile memory. This assures that the receiver operation will be restored whenever power is cycled or a power interruption occurs.
The front panel contains a stereo headphone connector, status indicator lights, and a power switch. Two rear coaxial input connectors allow RF sources (antennas) to be either independently connected between the receiver DCR section (2 to 2000 MHz) and the hybrid converter section (0.005 to 30 MHz), or using the RF output (2 to 30 MHz) connected to the hybrid converter section. The two frequency tuning ranges can be multiplexed internally from a single antenna. The rear 9-pin serial control connector allows for RS-232/RS-422/RS-485 control. Independently adjustable left and right phone channels are available on the headphone connector. The rear panel audio connector provides access to a variety of audio signals including speaker, line, and phone outputs.