A new narrow-band notch filter using a planar dual mode ring resonator (FCR) is presented. The resonator operates at harmonic frequencies and is manufactured on a temperature stable calcium magnesium titanate substrate, using photo-Lithographic thinfilm processes. An innovative fully automated active laser-trimming procedure is used to adjust the center frequency and the bandwidth of the filter.High unloaded quality factors of more than 400 have been obtained at Ka-baud frequencies. With these high quality factors a 3dBbandwidth of less than 1% in conjunction with a notch depth of more than 40dB can be achieved. In addition, the frequency tuning range of the laser-trimming is larger than 10% without any significant change of the filter characteristic or the quality factor of the resonator. The measured temperature coefficient of the filter is -2ppmJK.We use a notch filter with an electrical length of four wavelengths to suppress the undesired residual local oscillator signal in the transmitter chain of our latest microwave Point-to-point (PP) and Point-to-Multipoint (PMP) transceivers.

Statistical Analysis of Broadband Bearing Errors under Interference Conditions ÜbersichtIn realen Peilumgebungen ist der direkten Welle, die sich ungestört zwischen der zu peilenden Quelle und dem Peiler ausbreitet, häufig eine Vielzahl von kohärenten Wellen überlagert. Dabei entstehen stationäre Interferenzfelder, durch die oftmals große Peilfehler verursacht werden. Im vorliegenden Bericht wird mit Mitteln der mathematischen Statistik gezeigt, daß bei der Peilung von transienten Quellen durch die Verwendung einer breitbandigen Auswertung eine erhebliche Reduktion der Peilfehler erreicht wird, die durch die ungünstigen Umgebungsbedingungen entstehen. Die Richtungsbestimmung erfolgt dabei mit Hilfe der zeitgemittelten Energiestromdichte. AbstractIn real cases of direction finding sites the direct wave, which propagates undisturbed between the source of interest and the direction finder, is superposed by a lot of coherent waves. This causes stationary fields of interference and often results in large bearing errors. This report shows by means of mathematical statistics that the bearing errors in direction finding of transient sources caused by unfavourable surrounding conditions can considerably be reduced through the use of a broadband evaluation. In order to obtain the direction of incidence the time-averaged energyflow density is determined and evaluated.Für die Dokumentation Peilen / Peilfehler / breitbandiger Peilfehler / Interferenz / Energiestromdichte / Statistik Einleitung

In the space business, there is typically a quite long period from the design and development of new technologies to their commercial use. Even comprehensive tests on ground cannot replace long-lasting experiments and tests in space. Such IOV (In Orbit Verification) activities provide the scientific basis for the introduction and application of new technologies and the necessary heritage for commercial satellite programs. The Heinrich-Hertz mission of a geostationary communication satellite with a planned life time of 15 years lead by the German Space Administration (DLR) establishes a valuable basis to verify new technologies scientifically in orbit over a long period of time and to gain heritage regarding their performance in space [1]. In addition, research institutes and the industry are enabled to perform numerous scientific and technological experiments over the full life time of 15 years. With this approach of the mission, the German Space Administration offers to the German satellite industry an outstanding advantage and gain in knowledge for the development of new communication technologies and their applications. The launch of the satellite is envisaged for 2016. The technical feasibility of the overall program was successfully demonstrated within a Phase A study. The major tasks for the payload responsible during Phase A have been: (1) survey and assessment of all proposed IOV-technologies, (2) development of a payload concept for the scientific-technical verification of the IOV-technologies.

A new Ka-band voltage controlled oscillator ( W O ) using a planar ring resonator (RR) and a GaAspHEMT microwave monolithic integrated circuit (MMIC) is presented. The resonator operates at harmonic frequencies and is manufactured on a temperature stable calcium magnesium titanate substrate using photo-lithographic thinfilm processes. An innovative fully automated active lasertrimming procedure is used to adjust the frequency of the free-running oscillator as well as the varactor tuning sensitivity. In addition, automated laser-trimming is used to equalize the electrical length between the ring resonator and the MMIC.High unloaded quality factors of more than 350 have been obtained for the harmonic ring resonator. With these high quality factors a single side-band phase noise of better than -1lOdBciHz is achieved at an offset frequency of 1MHz. In addition, the frequency tuning range of the laser-trimming procedure is larger than 10% without any significant change of the VCO's characteristics like phase noise and varactor tuning sensitivity. The typical temperature drift of the oscillator frequency is less than 4ppmlK.We use a RR-VCO with an electrical length of four wavelengths, which is phase-locked to an external reference, as local oscillator in our latest microwave Point-to-Multipoint (PMP) transceivers.

Der Einfluß des menschlichen Körpers auf die elektrischen und magnetischen Feldkomponenten in unmittelbarer Nähe des KörpersAbstract Warning devices and meters are necessary for personal safety in radio frequency (RF) and microwave electromagnetic fields. The relevant standards and guidelines dictate that the respective field strength must be displayed that would exist if no one were present in the field. Accordingly, we must first determine to what extent the presence of a human body influences the individual electric and magnetic field components. Extensive computer-based computations were performed to this end. With the results obtained, a field strength meter for personal safety applications was developed which exhibits significant advantages over previous solutions. ÜbersichtFür den Personenschutz in hochfrequenten elektromagnetischen Feldern sind Warn-und Meßgeräte notwendig. Die entsprechenden Normen und Richtlinien fordern, daß diejenige Feldstarke angezeigt wird, die ohne Anwesenheit der betreffenden Person herrschen würde. Damit ist zunächst zu klären, in welchem Umfang die einzelnen elektrischen und magnetischen Feldkomponenten durch die Anwesenheit des menschlichen Körpers beeinflußt werden. Hierzu wurden umfangreiche Computerberechnungen durchgeführt. Unter Berücksichtigung der dabei erzielten Ergebnisse konnte ein Feldstärkemeßgerät für den Personenschlitz entwickelt werden, das erhebliche Vorteile gegenüber bisherigen Lösungen aufweist.Für die Dokumentation Feldstärkenmeßgerät / Elektromagnetische Umgebungskompatibilität / Meßgenauigkeit / menschPcher Körper