摘要:

The paper analyses a concept of noise equalization that can be applied in order to reduce the noise contribution due to intermodulation effects without affecting the basic signal to noise performance. Some practical applications of the noise equalization technique are outlined and the resulting operational benefits demonstrated.

DOI:10.1049/ree.1977.0028

出版商:IERE    

年代:1977

数据来源: IET

摘要:

The effective difference in sensitivity between two types of detection threshold is derived. They are a single threshold placed on the envelope of a complex signal, and a pair of thresholds placed on the modulus of each of the resolved quadrature components. It is shown that the loss which results for the sub-optimal case is acceptably small.

DOI:10.1049/ree.1977.0029

出版商:IERE    

年代:1977

数据来源: IET

摘要:

Delay-stabilized surface acoustic wave oscillators are attractive for use as stable, low-noise sources in digital frequency synthesizers for mobile radio. Here the design and operating principles of the surface acoustic wave oscillator are briefly reviewed. Its application is subsequently detailed in three experimental frequency synthesizer modules, which phase lock the surface acoustic wave oscillator to a reference crystal oscillator to achieve the superior stabilization required in mobile radio applications. First a single channel u.h.f. synthesizer is described which possesses superior efficiency when compared with conventional frequency multiplier based transmitters. Later digital dividers are added extending this module into multichannel synthesizers which ultimately have potential applications in h.f., v.h.f. and u.h.f. mobile radio systems.

DOI:10.1049/ree.1977.0030

出版商:IERE    

年代:1977

数据来源: IET

摘要:

A new triangle-to-sine shaper circuit is described based upon the modified transfer function of a differential pair of transistors. Computer-aided design techniques have been used to establish an optimized set of design criteria. Theoretical figures as low as six parts per million total harmonic distortion (t.h.d.) are possible with the circuit. Measurements taken on a prototype have fulfilled the promise of the circuit with t.h.d. figures of better than 0.05% with operation to 106hertz.

DOI:10.1049/ree.1977.0031

出版商:IERE    

年代:1977

数据来源: IET

摘要:

A method is presented for theoretical synthesis of loaded broadband cylindrical antenna with minimized input susceptance. Such an RC-loaded antenna was synthesized and realized, having the v.s.w.r. with respect to a real impedance of about 1.1 in a frequency range of almost 3:1, thus being probably the best cylindrical broadband antenna available. The antenna radiation pattern was found to be reasonably stable in the whole frequency range.

DOI:10.1049/ree.1977.0032

出版商:IERE    

年代:1977

数据来源: IET

摘要:

A method is presented for synthesis of the optimal broadband cylindrical monopole antenna with two closely spaced identical parasitic elements. The proximity and end effects are taken approximately into account, which results in a better agreement between theoretical and experimental results. A very flexible experimental model is described, which even allows an experimental synthesis of the antenna.

DOI:10.1049/ree.1977.0033

出版商:IERE    

年代:1977

数据来源: IET

摘要:

In order to gain practical experience of reception of television from satellites, a long-term experiment has been set up in Canada. The ground receiving station equipment and the monitoring arrangements are described.

DOI:10.1049/ree.1977.0034

出版商:IERE    

年代:1977

数据来源: IET