Патент USA US2128750код для вставки
Aug. 30, 1938. 2,128,750 w. KRIEBEL ULTRA~SHORT WAVE REEJEIVING APPARATUS Filed Oct. 28, 1937 47 INVENTOR. __ BY 7 _ A / El? KRIEBEL ' ATTOIQVEY. Patented Aug. 30, 1938 2,128,750 UNITED STATES PATENT orncr: 2,128,750 ULTRA- SHORT WAVE RECEIVING APPA RATUS Walter Kriebel, Berlin, Germany, assignor to Telei'unken Gesellschai't fiir Drahtlose Tele graphic 111. b. 11., Berlin, Germany, a corpo ration of Germany Application October 28, 1937, Serial No. 171,443 Germany S eptember 2, 1936 3 Claims. (Cl. 250-271) The present invention relates to a tube vde ing embodiments of the invention are shown. tector for receiving ultra-short waves. This de tector is more sensitive than a bolometer and exhibits above all a uniform response. The inventive idea is as follows: The emission source or cathode of a discharge tube, e. g. of a diode, is directly supplied with the high-frequency receiving current so that heating or additional heating is effected thereby. 10 As the emission of a cathode, so long as the ap— plied plate voltage by far exceeds the saturation voltage, greatly depends on the heating, relatively small variations of the receiving currents may be made perceptible in this manner. E. g. a heat 15 ing current variation by 1% yields an emission variation of about 20%. One reason why the plate voltage must exceed saturation voltage is to prevent space charge between the cathode and the plate. 20 ’ A relatively simple arrangement results, if a diode is used as receiving tube and one dipole half each is attached to the ends of the straight cathode. - As the ?lament energy consumption varies for a given resistance of the spot to be heated with the square of the current the cathode, pref erably, is initially heated by a constant but ad justable, as may be required, direct current and the received high-frequency oscillations are used only to render an additional heating. To avoid the high-frequency leaking off through the heat , ing current leads, one may either design the emissive spot to be very small so that it prac= tically lies only in the voltage node of the dipole, w or tune the heating current leads by means of a metal slider which is insulated from the heating current leads and is sliding on them. Further, one may shape the emissive spot to an indirectly ‘ heated cathode. In this case the heater is shaped Therein is designated by: , I the plate of a directly heated diode 9; 2 and 3 a dipole joined to the terminals of the ?la ment 4 (2 and 3 are tuned to M2 of the decimeter wave to be received); 5 a variable resistance for adjusting the heating current supplied by the heating battery 6 and thereby at the same time the emission of the ?lament 4 to the most fa vourable value, ‘I an indicator, e. g. a head phone, 8 the plate battery. The ?lament consists of a 10 tungsten-, thoriated or oxide-coated wire. The oxide-coated ?lament, e. g., is made of a core of platinum or a platinum-iridium alloy to which oxides of the alkaline earth metals, as calcium-, 15 strontium- or barium-oxide, together with var ious admixtures are pasted, fused or sintered on. The performance of the device is as follows: The modulated high-frequency, which oscil lates on the dipole together with the inserted . ?lament, varies the heating and thereby the emis sion'of the ?lament in time with the modulating amplitude. The emission variations produce plate current variations in the plate circuit, which are listened to by means of head phones either directly or through an ampli?er, To reduce still more the thermal inertia of the ?lament, the ?lament 4 may be given the shape of a platinum tube about 2p. in thickness, which is covered with oxides, if required. Fig. 2 shows practically the same receiving de 30 vice as Fig. 1. Like reference numerals represent like circuit elements. Only the cathode 10 has been varied. The preferably thin-walled emis sive sleeve is initially heated by a heater being situated within the sleeve. The wires of 35 the heater are running in opposite directions and led out at‘the centre of the emissive sleeve. In Fig. 3 an arrangement is shown in its prin to run bi?larly within the emission layer support - ciple, adapted in particular to receive very short and the lead-in wires are placed. exactly at the waves. To avoid losses at the seals of the dipole 40 voltage node. With extraordinary short waves it through the wall of the vessel and to be able to may occur) that the small dipole halves intended make the radiation collecting part without the to collect the radiation ‘lie at the greater part vessel of su?icient length, the whole arrange ,5 within the vacuum vessel or in the wall of the ' ment comprising the radiation collector and the tube. In such case it is recommendable to make cathode, has been made equal to an odd number 45 the radiation collector equal to'an odd number of half wave lengths, e. g. 3/2)., 5/2ll etc. The of half wave lengths, e. g. 3/2)\, and to arrange cathode II and the seals l2 and I3 are positioned that one voltage node each lies in the centre each at one voltage node of the stationary waves ‘0 or the emissive spot and at the seals through the ' built up on the total arrangement. 50 wall of the vessel respectively; or, alternately, In the operation of the device of the invention, one mounts the tuned dipoles, i. e. dipole de it will be appreciated that the extra ?lament ‘signed to have a certain length, together with the heating provided by the waves collected by the emission source within the vacuum. vessel. antenna gives plate current in proportion to the In the Figs. 1 to 3 of the accompanying draw amplitude of the extra heating current,- and hence 65 2 2,128,750 _Q.' in proportion to the amplitude of the received minals or the cathode of saiddischarge device, waves. This extra plate current, varying in ac cordance with the wave amplitude, constitutes a an indicator coupled to the plate circuit‘ of said discharge device, the said radiation collectors to gether with said cathode being so arranged that the total length is an odd multiple including unity modulation frequency current through the head phones. ‘ What is claimed is: 1. A tube detector comprising a space dis charge device, radiation collectors attached to the terminals of the cathode of said discharge device, 10 an indicator coupled to the plate' circuit of said discharge device, the said radiation collectors to gether with said cathode being so arranged that the total length amounts to 3/2x and 'one voltage node each occurs at the seals through the wall 15 of the device and at the centre of said cathode where A is the length of the collected wave. 2. A tube detector comprising a space discharge ‘ device, radiation collectors attached to the ter of half the length of the collected wave. 3. A tube detector comprising a space discharge device, radiation collectors attached to the ter minals of the cathode of said discharge device, an indicator coupled to the plate circuit of said ' discharge device, the said radiation collectors to gether with said‘ cathode being so arranged that the total length is an odd multiple including unity of half the length of the collected wave, and a voltage node occurs at the center of said cathode. WALTER KRIEBEL.